In the past 20 years, bug hunting has transformed from a hobby (or maybe even a felony) to a full-time profession for tens of thousands of talented software engineers around the globe. Thanks to the growth in private and public bug bounty programs, men and women with the talent can earn a good living by sniffing out flaws in the code for applications and – increasingly -physical devices that power the 21st century global economy. 

Asus ShadowHammer suggests Supply Chain Hacks are the New Normal

Bug Hunting Smart TVs To Supply Chain

What does that work look like and what platforms and technologies are drawing the attention of cutting edge vulnerability researchers? To find out we sat down with the independent researcher known as Sick Codes (@sickcodes). In recent months, he has gotten attention for a string of important discoveries. Among other things, he discovered flaws in Android smart television sets manufactured by the Chinese firm TCL and was part of the team, along with last week’s guest John Jackson, that worked to fix a serious server side request forgery flaw in a popular open source security module, NPM Private IP

Spotlight Podcast: How Machine Learning is revolutionizing Application Fuzzing

In this interview, Sick Codes and I talk about his path to becoming a vulnerability researcher, the paid and unpaid research he conducts looking for software flaws in common software and internet of things devices, some of the challenges and impediments that still exist in reporting vulnerabilities to corporations and what’s in the pipeline for 2021. 


As always,  you can check our full conversation in our latest Security Ledger podcast at Blubrry. You can also listen to it on iTunes and check us out on SoundCloudStitcherRadio Public and more. Also: if you enjoy this podcast, consider signing up to receive it in your email. Just point your web browser to securityledger.com/subscribe to get notified whenever a new podcast is posted. 

In this episode of the podcast (#200), sponsored by Digicert: John Jackson, founder of the group Sakura Samurai talks to us about his quest to make hacking groups cool again. Also: we talk with Avesta Hojjati of the firm Digicert about the challenge of managing a growing population of digital certificates and how  automation may be an answer.


Life for independent security researchers has changed a lot in the last 30 years. The modern information security industry grew out of pioneering work by groups like Boston-based L0pht Heavy Industries and the Cult of the Dead Cow, which began in Lubbock, Texas.

After operating for years in the shadows of the software industry and in legal limbo, by the turn of the millennium hackers were coming out of the shadows. And by the end of the first decade of the 21st century, they were free to pursue full fledged careers as bug hunters, with some earning hundreds of thousands of dollars a year through bug bounty programs that have proliferated in the last decade.

Despite that, a stigma still hangs over “hacking” in the mind of the public, law enforcement and policy makers. And, despite the growth of bug bounty programs, red teaming and other “hacking for hire” activities, plenty of blurry lines still separate legal security research from illegal hacking. 

Hacks Both Daring…and Legal

Still, the need for innovative and ethical security work in the public interest has never been greater. The Solar Winds hack exposed the ways in which even sophisticated firms like Microsoft and Google are vulnerable to compromised software supply chain attacks. Consider also the tsunami of “smart” Internet connected devices like cameras, television sets and appliances are working their way into homes and workplaces by the millions. 

Podcast Episode 112: what it takes to be a top bug hunter

John Jackson is the co -founder of Sakura Samurai, an independent security research group. 

What does a 21st century hacking crew look like? Our first guest this week is trying to find out. John Jackson (@johnjhacking) is an independent security researcher and the co-founder of a new hacking group, Sakura Samurai, which includes a diverse array of security pros ranging from a 15 year old Australian teen to Aubrey Cottle, aka @kirtaner, the founder of the group Anonymous. Their goal: to energize the world of ethical hacking with daring and attention getting discoveries that stay on the right side of the double yellow line.

Update: DHS Looking Into Cyber Risk from TCL Smart TVs

In this interview, John and I talk about his recent research including vulnerabilities he helped discover in smart television sets by the Chinese firm TCL, the open source security module Private IP and the United Nations. 

Can PKI Automation Head Off Chaos?

One of the lesser reported sub plots in the recent Solar Winds hack is the use of stolen or compromised digital certificates to facilitate compromises of victim networks and accounts. Stolen certificates played a part in the recent hack of Mimecast, as well as in an attack on employees of a prominent think tank, according to reporting by Reuters and others. 

Avesta Hojjati is the head of Research & Development at Digicert.

How is it that compromised digital certificates are falling into the hands of nation state actors? One reason may be that companies are managing more digital certificates than ever, but using old systems and processes to do so. The result: it is becoming easier and easier for expired or compromised certificates to fly under the radar. 

Our final guest this week, Avesta Hojjati, the  Head of R&D at DigiCert, Inc. thinks we’ve only seen the beginning of this problem. As more and more connected “things” begin to populate our homes and workplaces, certificate management is going to become a critical task – one that few consumers are prepared to handle.

Episode 175: Campaign Security lags. Also: securing Digital Identities in the age of the DeepFake

What’s the solution? Hojjati thinks more and better use of automation is a good place to start. In this conversation, Avesta and I talk about how digital transformation and the growth of the Internet of Things are raising the stakes for proper certificate management and why companies need to be thinking hard about how to scale their current certificate management processes to meet the challenges of the next decade. 


(*) Disclosure: This podcast was sponsored by Digicert. For more information on how Security Ledger works with its sponsors and sponsored content on Security Ledger, check out our About Security Ledger page on sponsorships and sponsor relations.

As always,  you can check our full conversation in our latest Security Ledger podcast at Blubrry. You can also listen to it on iTunes and check us out on SoundCloudStitcherRadio Public and more. Also: if you enjoy this podcast, consider signing up to receive it in your email. Just point your web browser to securityledger.com/subscribe to get notified whenever a new podcast is posted. 

The acting head of the U.S. Department of Homeland Security said the agency was assessing the cyber risk of smart TVs sold by the Chinese electronics giant TCL, following reports last month in The Security Ledger and elsewhere that the devices may give the company “back door” access to deployed sets.

Speaking at The Heritage Foundation, a conservative think tank, Acting DHS Secretary Chad Wolf said that DHS is “reviewing entities such as the Chinese manufacturer TCL.”

“This year it was discovered that TCL incorporated backdoors into all of its TV sets exposing users to cyber breaches and data exfiltration. TCL also receives CCP state support to compete in the global electronics market, which has propelled it to the third largest television manufacturer in the world,” Wolf said, according to a version of prepared remarks published by DHS. His talk was entitled “Homeland Security and the China Challenge.”

As reported by The Security Ledger last month, independent researchers John Jackson, (@johnjhacking) -an application security engineer for Shutter Stock – and a researcher using the handle Sick Codes (@sickcodes) identified and described two serious software security holes affecting TCL brand television sets. The first, CVE-2020-27403, would allow an unprivileged remote attacker on the adjacent network to download most system files from the TV set up to and including images, personal data and security tokens for connected applications. The flaw could lead to serious critical information disclosure, the researchers warned.

Episode 197: The Russia Hack Is A 5 Alarm Fire | Also: Shoppers Beware!

The second vulnerability, CVE-2020-28055, would have allowed a local unprivileged attacker to read from- and write to critical vendor resource directories within the TV’s Android file system, including the vendor upgrades folder.

Both flaws affect TCL Android Smart TV series V8-R851T02-LF1 V295 and below and V8-T658T01-LF1 V373 and below, according to the official CVE reports. In an interview with The Security Ledger, the researcher Sick Codes said that a TCL TV set he was monitoring was patched for the CVE-2020-27403 vulnerability without any notice from the company and no visible notification on the device itself.

In a statement to The Security Ledger, TCL disputed that account. By TCL’s account, the patched vulnerability was linked to a feature called “Magic Connect” and an Android APK by the name of T-Cast, which allows users to “stream user content from a mobile device.” T-Cast was never installed on televisions distributed in the USA or Canada, TCL said. For TCL smart TV sets outside of North America that did contain T-Cast, the APK was “updated to resolve this issue,” the company said. That application update may explain why the TCL TV set studied by the researchers suddenly stopped exhibiting the vulnerability.

DHS announces New Cybersecurity Strategy

While TCL denied having a back door into its smart TVs, the company did acknowledge the existence of remote “maintenance” features that could give its employees or others control over deployed television sets, including onboard cameras and microphones. Owners must authorize the company to access cameras and microphones, however, according to a company statement.

The company did not address in its public statements the question of whether prior notification of the update was given to TCL owners or whether TV set owners were given the option to approve the update before it was installed.

Sick Codes, in a phone interview with The Security Ledger, said the company’s ability to push and update code to its deployed sets without owner approval amounted to a back door that could give TCL access to audio and video streams from deployed sets, regardless of the wishes of owners.

“They can update the application and make authorization happen through that. They have full control,” he said.

Such concerns obviously raised alarms within the Department of Homeland Security as well, which has taken steps to ban technology from other Chinese firms from use on federal networks.

In his address on Monday, Acting Secretary Wolf said the warning about TCL will be part of a a broader “business advisory” cautioning against using data services and equipment from firms linked to the People’s Republic of China (PRC).

This advisory will highlight “numerous examples of the PRC government leveraging PRC institutions like businesses, organizations, and citizens to covertly access and obtain the sensitive data of businesses to advance its economic and national security goals,” Wolf said.

“DHS flags instances where Chinese companies illicitly collect data on American consumers or steal intellectual property. CCP-aligned firms rake in tremendous profits as a result,” he said.

The statement is part of escalating tensions between Washington and Beijing. On Friday, Commerce Secretary Wilbur Ross announced export controls on 77 Chinese companies including the country’s biggest chipmaker, SMIC, and drone maker DJI that restrict those firms’ access to US technology. The order cites those firms alleged ties to China’s military.

TCL did not respond to an email request for comment prior to publication of this story. We will update this story as more information becomes available.


Editor’s note: this story was updated to add reference to John Jackson, who helped discover the TCL vulnerabilities. – PFR 12/22/2020

Between Black Friday and Cyber Monday, consumers across the U.S. spent the weekend snapping up deals on home electronics like smart TVs, game consoles and appliances. Total season-to date holiday spending, including Cyber Monday, is over the $100 billion threshold according to data from Adobe. 

Lots of factors drive consumer decisions to buy one product over another: price and features chief among them. But what about cyber security? Unlike, say, the automobile marketplace, concerns about safety and security are not top of mind when consumers step into a Best Buy or Wal Mart looking for a new flat screen TV. And ratings systems for cyber security, from organizations like UL and Consumer Reports, are in their infancy and not widely used.

Episode 170: Cyber Monday is for Hackers

found to have numerous, serious security flaws that could have left it open to remote access and data theft – all without need of a login or password. And TCL acknowledged to Security Ledger that access to on-board cameras and microphones is available to company support personnel, though only with the permission of the owner, according to a company statement.  

This isn’t a new occurrence. Consumer Reports warned in 2018 about vulnerabilities in smart TVs by Samsung, TCL and Roku that used Roku’s smart TV platform.

Expert: Patch Bluekeep Now or Face WannaCry Scenario

But concerns about the cyber security of smart home electronics go way beyond TVs. As our guest this week, Yossi Appleboum of the firm Sepio Systems tells us, software and hardware supply chains are rife with vulnerable – if not compromised components. And companies, like consumers, often have no idea whether a product they’ve deployed might be secretly spying on them, or channeling sensitive data to an unknown party or country. 

While many organizations think the notion of keyboards, monitors and other hardware “spying” on them as the stuff of “James Bond” movies, Appleboum says that the threat is real – and much more common that either companies or consumers are aware.

Podcast Episode 128: Do Security and Privacy have a Booth at CES?

Appleboum’s firm, Sepio Systems, provides visibility, policy enforcement and “rogue” device mitigation capabilities, to organizations concerned about the risks posed by hardware assets.

In this conversation, Yossi and talk about the supply chain security risk and how concerned consumers should be about the security of electronic devices being pushed on them this holiday season. 


As always,  you can check our full conversation in our latest Security Ledger podcast at Blubrry. You can also listen to it on iTunes and check us out on SoundCloudStitcherRadio Public and more. Also: if you enjoy this podcast, consider signing up to receive it in your email. Just point your web browser to securityledger.com/subscribe to get notified whenever a new podcast is posted. 

Chinese electronics giant TCL has acknowledged security holes in some models of its smart television sets, but denies that it maintains a secret “back door” that gives it control over deployed TVs.

In an email statement to The Security Ledger dated November 16, Senior Vice President for TCL North America Chris Larson acknowledged that the company issued a security patch on October 30 for one of two serious security holes reported by independent researchers on October 27. That hole, assigned the Common Vulnerabilities and Exposure (CVE) number 2020-27403 allowed unauthenticated users to browse the contents of a TCL smart TV’s operating system from an adjacent network or even the Internet.

A patch for a second flaw, CVE-2020-28055, will be released in the coming days, TCL said. That flaw allows a local unprivileged attacker to read from- and write to critical vendor resource directories within the TV’s Android file system, including the vendor upgrades folder.

The Security Ledger reported last week on the travails of the researchers who discovered the flaws, @sickcodes and @johnjhacking, who had difficulty contacting security experts within TCL and then found a patch silently applied without any warning from TCL.

A Learning Process for TCL

In an email statement to Security Ledger, Larson acknowledged that TCL, a global electronics giant with a market capitalization of $98 billion, “did not have a thorough and well-developed plan or strategy for reacting to issues” like those raised by the two researchers. “This was certainly a learning process for us,” he wrote.

At issue was both the security holes and the manner in which the company addressed them. In an interview with The Security Ledger, the researcher using the handle Sick Codes said that a TCL TV set he was monitoring was patched for the CVE-2020-27403 vulnerability without any notice from the company and no visible notification on the device itself.

IT Asset Disposition (ITAD) is the Slow Motion Data Breach Nobody notices

By TCL’s account, the patch was distributed via an Android Package (APK) update on October 30. APK files are a method of installing (or “side loading”) applications and code on Android-based systems outside of sanctioned application marketplaces like the Google Play store. The company did not address in its public statements the question of whether prior notification of the update was given to customers or whether TV set owners were required to approve the update before it was installed.

Limited Impact in North America

However, the patch issued on October 30 is unlikely to have affected TCL customers in the U.S. and Canada, as none of the TCL models sold in the North America contain the CVE-2020-24703 vulnerability, TCL said in its statement. However, some TCL TV models sold in the U.S. and Canada are impacted by CVE-2020-28055, the company warned. They are TCL models 32S330, 40S330, 43S434, 50S434, 55S434, 65S434, and 75S434.

The patched vulnerability was linked to a feature called “Magic Connect” and an Android APK by the name of T-Cast, which allows users to “stream user content from a mobile device.” T-Cast was never installed on televisions distributed in the USA or Canada, TCL said. For TCL smart TV sets outside of North America that did contain T-Cast, the APK was “updated to resolve this issue,” the company said. That application update may explain why the TCL TV set studied by the researchers suddenly stopped exhibiting the vulnerability.

Consumer Reports: Flaws Make Samsung, Roku TVs Vulnerable

No Back Doors, Just “Remote Maintenance”

While TCL denied having a back door into its smart TVs, the company did acknowledge the existence of remote “maintenance” features that could give its employees or others control over deployed television sets, including onboard cameras and microphones.

In particular, TCL acknowledges that an Android APK known as “Terminal Manager…supports remote diagnostics in select regions,” but not in North America. In regions where sets with the Terminal Manager APK are deployed, TCL is able to “operate most functions of the television remotely.” That appears to include cameras and microphones installed on the set.

However, TCL said that Terminal Manager can only be used if the user “requests such action during the diagnostic session.” The process must be “initiated by the user and a code provided to TCL customer service agents in order to have diagnostic access to the television,” according to the company’s FAQ.

Other clarifications from the vendor suggest that, while reports of secret back doors in smart TVs may be overwrought, there is plenty of reason to worry about the security of TCL smart TVs.

The TCL statement acknowledged, for example, that two publicly browsable directories on the TCL Android TVs identified by the researchers could have potentially opened the door for malicious actors. A remotely writeable “upgrade” directory /data/vendor/upgrade on TCL sets has “never been used” but is intended for over the air firmware upgrades. Firmware update files placed in the directory are loaded on the next TV reboot. Similarly a directory /data/vendor/tcl, has also “never been used,” but stores “advertising graphics” that also are loaded “as part of the boot up process,” TCL said.

Promises to work with Independent Researchers

The company said it has learned from its mistakes and that it is undertaking efforts to work more closely with third party and independent security researchers in the future.

“Going forward, we are putting processes in place to better react to discoveries by 3rd parties. These real-world experts are sometimes able to find vulnerabilities that are missed by testing. We are performing additional training for our customer service agents on escalation procedures on these issues as well as establishing a direct reporting system online,” the company said.

China Risk Rising

Vendor assurances aside, there is growing concern within the United States and other nations about the threat posed by hundreds of millions of consumer electronic devices manufactured – or sourced in China. The firm Intsights in August warned that China was using technological exports as “weaponized trojans in foreign countries.” The country is “exporting technology around the world that has hidden backdoors, superior surveillance capability, and covert data collection capabilities that surpass their intended purposes and are being used for widespread reconnaissance, espionage, and data theft,” the company warned, citing reports about gear from the telecommunications vendor Huawei and social media site TikTok among others.

Western governments and non-governmental organizations have also raised alarms about the country’s blend of technology-enabled authoritarianism, including the use of data theft and data harvesting, coupled with artificial intelligence to identify individuals whose words or actions are counter to the ruling Communist Party.

Binary Check Ad Blocker Security News

Millions of Android smart television sets from the Chinese vendor TCL Technology Group Corporation contained gaping software security holes that researchers say could have allowed remote attackers to take control of the devices, steal data or even control cameras and microphones to surveil the set’s owners.

The security holes appear to have been patched by the manufacturer in early November. However the manner in which the holes were closed is raising further alarm among the researchers about whether the China-based firm is able to access and control deployed television sets without the owner’s knowledge or permission.

Two Flaws, Lots of Red Flags

In a report published on Monday, two security researchers described two serious software security holes affecting TCL brand television sets. First, a vulnerability in the software that runs TCL Android Smart TVs allowed an attacker on the adjacent network to browse and download sensitive files over an insecure web server running on port 7989.

More Questions as Expert Recreates Chinese Super Micro Hardware Hack

That flaw, CVE-2020-27403, would allow an unprivileged remote attacker on the adjacent network to download most system files from the TV set up to and including images, personal data and security tokens for connected applications. The flaw could lead to serious critical information disclosure, the researchers warned.

Consumer Reports: Flaws Make Samsung, Roku TVs Vulnerable

Second, the researchers found a vulnerability in the TCL software that allowed a local unprivileged attacker to read from- and write to critical vendor resource directories within the TV’s Android file system, including the vendor upgrades folder. That flaw was assigned the identifier CVE-2020-28055.

Both flaws affect TCL Android Smart TV series V8-R851T02-LF1 V295 and below and V8-T658T01-LF1 V373 and below, according to the official CVE reports.

John Jackson is an application security engineer at Shutterstock.

The researchers, John Jackson, an application security engineer for Shutter Stock, and the independent researcher known by the handle “Sick Codes,” said the flaws amount to a “back door” on any TCL Android smart television. “Anybody on an adjacent network can browse the TV’s file system and download any file they want,” said Sick Codes in an interview via the Signal platform. That would include everything from image files to small databases associated with installed applications, location data or security tokens for smart TV apps like Gmail. If the TCL TV set was exposed to the public Internet, anyone on the Internet could connect to it remotely, he said, noting that he had located a handful of such TCL Android smart TVs using the Shodan search engine.

CVE-2020-28055 was particularly worrisome, Jackson said. “It was clear that utilizing this vulnerability could result in remote code execution or even network ‘pivots’ by attackers.” That would allow malicious actors to move from the TV to other network connected systems with the intention of exploiting systems quickly with ransomware, Jackson observed. That, coupled with a global population of millions of TCL Android TVs, made the risk considerable.

Nobody Home at TCL

The researchers said efforts to alert TCL about the flaws in October initially fell on deaf ears. Emails sent to a designated email address for reporting security issues bounced. And inquiries to the company on October 16 and 20th went unanswered. Furthermore, the company did not appear to have a dedicated product security team to reach out to, Jackson said in a phone interview.

A screen shot of the browse-able file system of a TCL television set.
A screen capture showing the full, browsable file system on an Internet-connected TCL television set.

Podcast Episode 128: Do Security and Privacy have a Booth at CES?

Only after reaching out to a security contact at TCL partner Roku did Sick Codes and Jackson hear from a security resource within TCL. In an email dated October 29th, Eric Liang of TCL wrote to the two researchers thanking them for their discovery and promising a quick fix.

“Here is how is it going on now: A new version to fix this vulnerability is going to release to SQA on Oct. 29 (UTC+8). We will arrange the upgrade plan after the regression test passes.”

Silent Patch Raises More Questions

Following that, however, there was no further communication. And, when that fix came, it raised more questions than it answered, the researchers said.

According to the researchers, TCL patched the vulnerabilities they had identified silently and without any warning. “They updated the (TCL Android) TV I was testing without any Android update notification or warning,” Sick Codes said. Even the reported firmware version on the TV remained unchanged following the patch. “This was a totally silent patch – they basically logged in to my TV and closed the port.”

Sick Codes said that suggests that TCL maintains full, remote access to deployed sets. “This is a full on back door. If they want to they could switch the TV on or off, turn the camera and mic on or off. They have full access.”

Jackson agreed and said that the manner in which the vulnerable TVs were updated raises more questions than it answers. “How do you push that many gigabytes (of data) that fast with no alert? No user notification? No advisory? Nothing. I don’t know of a company with good security practices that doesn’t tell users that it is going to patch.”

There was no response to emails sent by Security Ledger to Mr. Liang and to TCL media relations prior to publication. We will update this story with any comment or response from the company when we receive it.

Questions on Smart Device Security

The vulnerabilities raise serious questions about the cyber security of consumer electronics that are being widely distributed to the public. TCL, a mainland Chinese firm, is among those that have raised concerns within the U.S. Intelligence community and among law enforcement and lawmakers, alongside firms like Huawei, which has been labeled a national security threat, ZTE and Lenovo. TCL smart TVs are barred from use in Federal government facilities. A 2019 U.S. Department of Defense Inspector General’s report raised warnings about the cyber security risks to the Pentagon of commercial off the shelf (COTS) technology purchased by the U.S. military including televisions, laptops, surveillance cameras, drones and more. (PDF)

And while disputes over Chinese apps like TikTok dominate the headlines,  a recent report from the firm IntSights on China’s growing cyber risk notes that the Chinese Communist Party (CCP) is engaged in a far broader campaign to elevate the country to superpower status by treating “data as the most valuable asset.”

The supply chain for a seemingly endless variety of technology sold and used in the United States originates in China. A 2019 study by the security firm Interos, for example, found that one fifth (20%) of the hardware and software components in a popular voting machine came from suppliers in China. Furthermore, close to two-thirds (59%) of components in that voting machine came from companies with locations in both China and Russia.

TCL has risen quickly in the past five years to become a leading purveyor of smart television sets in the U.S. with a 14% market share, second behind Samsung. The company has been aggressive in both partnerships and branding: teaming with firms like Alcatel Mobile and Thompson SA to produce mobile phones and other electronics, and sponsoring sports teams and events ranging from the Rose Bowl in Pasadena, California, to The Ellen Show to the 2019 Copa América Brasil soccer tournament.

TCL’s TV sets are widely available in the US via online e-tailers like Amazon and brick and mortar “box stores” like Best Buy. It is unclear whether those retailers weigh software security and privacy protections of products before opting to put them on their store shelves. An email to Best Buy seeking comment on the TCL vulnerabilities was not returned.

Buyer Beware

The security researchers who discovered the flaw said that consumers should beware when buying smart home electronics like TV sets, home surveillance cameras, especially those manufactured by companies with ties to authoritarian regimes.

“Don’t buy it just because a TVs cheap. Know what you’re buying,” said Sick Codes. “That’s especially true if it’s hooked up to the Internet.”