The company Espressif has had 35 documented security and bug advisories since 2020, ranging from genuine security flaws to end-of-life announcements. That’s a lot. However their newest entry, labeled CVE-2025-27840 out of Spain regarding an ESP32 chip, stands out not for its discovery but for its alarmist classification.

To be clear, the latest security advisory in Espressif’s catalog follows a dozen in 2024 alone, including fun ones like “Bypassing Secure Boot and Flash Encryption using CPA and FI attack” (AR2023-007) and “Security Advisory for WLAN FragAttacks” (AR2023-008).

That’s why I say to begin, looking at the ESP32, we shouldn’t be surprised. I mean if a kid driving an industrial harvester has found something to chew on in the exact same field that for the last five years has produced a whole lot of delicious potatoes, that’s expected, right?

Now for the meat of the issue with this CVE, as reported. When researchers Miguel Tarascó Acuña and Antonio Vázquez Blanco announced their findings at RootedCON in Madrid, they used the term “backdoor” for an ESP32 Bluetooth implementation.

However, where the prior litany of vulnerability reports represented actual attack vectors with demonstrable exploitation paths, their claim comes up short by comparison. It deserves a rebuff through some rational technical dissection that uses a baseline to verify backdoor claims.

Examining their actual discovery reveals something rather mundane in the security vulnerability hierarchy: undocumented vendor commands residing precisely where the Bluetooth specification expects vendor commands to exist—in OGF (Opcode Group Field) 0x3F.

We should be fair to prior researchers, not to mention Espressif’s track record of proper vulnerability disclosure. Applying a consistent technical rigor of research to the new CVE greatly waters down claims being made. It simply doesn’t hold a candle to actual hairy security like a June 2021 (AR2021-002) flash encryption flaw.

Flash 中的分区表本身也经过加密，但攻击者⼀一旦具备对设备的物理理访问权限，则有可能
篡改经过加密的分区表，并清除⼀一些分区的 “加密” 标记。这样⼀一来，设备在下次启动时将
视这些分区为明⽂文数据来处理理

Be honest now, are you scared more because I said encryption flaw, or because you’re seeing Chinese?

An undocumented command set of course could sound very, very scary to an untrained ear, to those who don’t read command sets and thus can’t understand what’s going on. So let’s dive in deep to apply some banal vulnerability taxonomy and see what commands actually were discovered versus what was waved on the plains of Spain like a big red cape to work up some bulls….

I guess we can call this doing research on the research, or even some peer review if you must, given disclosure of vendor-specific HCI (Host Controller Interface) commands. I will try here to make a significant technical distinction, with important security implications, to explain why a backdoor doesn’t seem to exist.

The researchers cleverly reverse-engineered the ESP32 firmware by analyzing multiple binary libraries provided by Espressif:

`libbtdm_app.a`
`libbttestmode.a`
`libphy.a`
`librftest.a`
`librtc.a`


Through static analysis with the NSA’s Ghidra (VROOM VROOM, push the big GO button), they discovered the ESP32 contains tables of HCI commands, with the last entry referencing OGF 0x3F—a range reserved for proprietary vendor commands.

This revealed 29 undocumented commands for low-level functionality.

Now for some bad news. A backdoor, by definition, implies some specific stuff. Any of this would help:

1. Intentional implementation for unauthorized access
2. Remote exploitability without prior access
3. Bypass of authentication mechanisms

The discovered ESP32 functionality however fails all three criteria:

Implementation Intent

I see proprietary debugging/manufacturing commands. The commands exist in the OGF 0x3F range explicitly designated for vendor-specific functionality in the Bluetooth specification. This is standard practice in hardware and software, across chipsets.

Access Vector

Exploitation requires sending HCI commands to the ESP32, which necessitates either having physical access to the device’s USB/UART interfaces, or a prior compromise allowing direct communication with the Bluetooth controller. Root access is needed to send arbitrary HCI commands.

Command Architecture

The commands use standard HCI protocol structure and are processed through the normal command handler. They aren’t hidden “backdoor” channels but rather undocumented extensions of the standard interface.

As you can see any claims of a backdoor stretch the definition beyond recognition. This is a case of documenting something missing a manual. Look at their discovered commands, which include:

0xFC01 - Read memory
0xFC02 - Write memory
0xFC32 - Set MAC address
0xFC0E - Send LMP packet
0xFC43 - Send LLCP packet


These are typical vendor testing/debugging functions found in most Bluetooth controllers. The commands are processed through usual RivieraWaves/CevaWaves RTOS command handlers—the proprietary Bluetooth stack used by ESP32.

With all the usual stuff in mind the actual security impact is limited to scenarios where an attacker has already achieved privileged access. In other words, calling this a backdoor is like entering a house somehow (front door, back door, window, whatever) and then saying “hey everyone I found a hidden closet in this bedroom, not on the floorplan”. Kinda significant difference from a backdoor event.

It’s still a hidden thing, on a proprietary chip, so let’s not forget some scenarios could manifest and maybe even matter to someone thinking broadly about risks.

OEMs, or someone intercepting chips, implementing an ESP32 could theoretically exploit these commands, but of course they already have physical access to modify firmware.

After gaining root access to a device with an ESP32, an attacker could use these commands to hide code in the controller—but again this requires some prior system wide compromise. Can’t use a hidden closet until after you get in the house somehow.

Physical access to debugging interfaces could allow firmware manipulation, just like virtually any embedded device. Nothing new here.

I guess what I’m saying is that it is fantastic to see someone put together undocumented functionality by applying “right to repair” principles. But it’s silly for them to call documentation of any of these functions a backdoor.

The security community should hold the line and classify it as CWE-912 (Hidden Functionality) rather than CWE-506 (Embedded Malicious Code).

While Espressif could document these commands for transparency (unless they want to give researchers something to busy themselves with), they seem to follow industry norms for proprietary extensions to a Bluetooth specification. It’s called proprietary for a reason.

The research is valuable to show Bluetooth security testing works, but the “backdoor” characterization is technically inaccurate and obviously misleading.

If there’s one thing for certain, Woz is an engineer and Musk is a snake-oil salesman.

It doesn’t take an engineer to explain why snake-oil can’t make anything better, only worse, but perhaps it helps.

…many Tesla owners have not liked software and UI (user interface) updates the company has implemented over time. Woz is definitely in that camp. “Every step up, where they changed things in the car, it got worse and worse and worse, and now it is just miserable for user interface,” he said. “Coming from Apple, user interface, the way you deal with technology, is the most important thing in the world to me — and Tesla is the worst in the world at that.” […] “And I’m just sick of that company, the support is so ridiculous.” […] “I’ve spoken on national TV shows about how he lied to us — about driving itself across the country by the end of 2016, and then by [the end of] 2017. And he got money from us, stole money from us…”

Worst in the world? Stole?

Ouch.

Woz calls Elon Musk’s tech the worst in the world, calls it a crime. Woz is legit. He knows tech. He’s an engineering legend. And I would say he knows a conman.

So why would anyone ever buy a Tesla?

Defense Secretary Pete Hegseth, who allegedly had been “mutually departed” from the military because of hate speech, just gave the U.S. military a few days to delete all military files that have the word “gay”.

…photos seemed to be flagged for removal simply because their file included the word ”gay,” including service members with that last name and an image of the B-29 aircraft Enola Gay, which dropped the first atomic bomb on Hiroshima, Japan, during World War II.

Several photos of an Army Corps of Engineers dredging project in California were marked for deletion, apparently because a local engineer in the photo had the last name Gay. And a photo of Army Corps biologists was on the list, seemingly because it mentioned they were recording data about fish — including their weight, size, hatchery and gender.

Records of women and minorities also are to be negligently axed from American military history. Already a WWII Medal of Honor recipient apparently has been negligently axed by Hegseth, seemingly for not being white enough.

Jeff Prosperie, who was struck by the ax thrown by Hegseth during a segment on the show, alleges that the co-host “negligently attempted to throw an axe…

Musk Personally Sabotaged American State-Run Rail, Then Praised Chinese Success in State-Run Rail: Who is He Really Fighting For?

“How can someone in Musk’s position have so many connections to China but still be a good person to reform the US government?” said Derek Scissors, a senior fellow at the American Enterprise Institute. The influx of Chinese money into Musk’s business empire “adds to this picture that he is more interested in his reputation and his brand in China than he is in American interests”.

In a recent appearance at the Morgan Stanley Technology Media & Telecom conference, Elon Musk declared that America should “privatize anything that can be privatized” when discussing the sorry state of American passenger rail.

This statement came just moments after praising China’s bullet trains – a completely state-owned and operated system that has become the world’s largest and most advanced high-speed rail network.

This shameless conman contradiction reveals a disturbing pattern: Musk himself deliberately undermined America’s best attempt to build state-run high-speed rail comparable to China’s, and now praises China’s state-run system while advocating for a privatization model that has failed everywhere it’s been tried. Does he really expect to be a front-man for the Chinese state buying up American critical infrastructure? Like how he became the front-man for Russia buying Twitter?

From Ruthless Railroad Barons to Toxic Tech Elites

The 19th century saw America’s original railroad barons build an extensive rail network that prioritized freight and profit over passenger service. These industrialists – Vanderbilt, Gould, Harriman, and others – created immoral empires through government land grants, favorable regulation, and ruthless business tactics.

Today, we see echoes of this era as tech billionaires like Musk insert themselves into transportation policy debates. But unlike the original barons who actually built physical infrastructure (however horrible and problematic their methods), Musk’s contribution to American passenger rail has been rhetorical and counterproductive.

I can’t emphasize enough how private companies operating essential infrastructure prioritize their short-term profits over long-term service availability let alone quality. When they face financial trouble, the public typically bears again the fully privatized costs through bailouts or service disruptions, totally contradicting Musk’s bogus claims about “feedback” loops.

Musk said “Basically something’s got to have some chance of going bankrupt or there’s not a good feedback loop for improvement.”

No, no and no. That’s not how infrastructure actually works. Privatized essential services don’t create “feedback loops” – they create extraction opportunities. When private companies take control of public infrastructure, they typically maximize short-term profit extraction, ignore maintenance needs, raise prices on captive customers, and when difficulties arise, demand government bailouts or declare bankruptcy – leaving taxpayers with the bill and degraded service. The executives and investors walk away enriched while the public infrastructure crumbles. It’s reminiscent of how oligarchic systems function: public assets are transferred to private hands, profits are privatized, and costs are socialized. The “feedback loop” Musk puffs up is an obvious calculated lie. It doesn’t exist in the real-world history of privatized infrastructure.

The Sabotage: Musk’s Deliberate Derailing of American High-Speed Rail

When California was advancing plans for its high-speed rail project in 2013, Musk unveiled his bogus Hyperloop concept – a hypothetical “efficiency” in transportation promising fantasy speeds at fantasy cost versus conventional rail. The timing wasn’t just convenient; it was calculated.

In Musk’s own words, captured in biographer Tim Higgins’ book “Power Play,” he admitted that slowing down California’s high-speed rail project was part of his motivation for propaganda about Hyperloop concepts that would never work.

This shocking admission reveals that undermining America’s flagship state-run rail project was a deliberate strategy to destroy modern rail projects, not an unintended consequence.

California’s high-speed rail plan represented America’s most serious attempt to create something comparable to China’s burgeoning rail network. The original vision called for 220 mph trains connecting San Francisco to Los Angeles in under three hours, with later extensions to Sacramento and San Diego. This would have created a unified economic mega-region, much like China has done with its Beijing-Shanghai corridor and Pearl River Delta connections.

The California project began with strong political momentum, $9 billion in state bond funding, and $3.5 billion in federal grants. It had the scale, ambition, and initial funding to become America’s showcase answer to Chinese rail innovation.

Musk’s targeted fraud came at a pivotal moment, offering politicians and the public a fantasy alternative that promised “efficiency” of faster, cheaper, and more… fantasy. The timing was devastating – it undercut public support just as the project faced its first major hurdles with land acquisition and regulatory approvals.

Over a decade later, no commercial Hyperloop system exists anywhere (because it was fraud), while California’s high-speed rail project has been dramatically scaled back from its original vision. The full San Francisco to Los Angeles route remains uncertain, with construction focused on a Central Valley segment that critics deride as “a train to nowhere.”

This wasn’t just a case of business fraud – it was a deliberate attack on the state, an act of sabotage against the type of state-run high-speed rail that Musk now praises in China.

The Hypocrisy: Praising State Success While Advocating Failed Privatization

Now, in a display of shameless hypocrisy, Musk stands before investors praising state-run trains – the very type of state-run system he helped undermine in America – while simultaneously advocating for ending state-run trains by privatizing Amtrak.

The expanding fraud behind the contradiction is impossible to ignore:

1. He praises China’s state-run rail system – the world’s largest and most successful high-speed network, built through massive government investment and centralized planning
2. He helped kill America’s attempt to build a similar state-run system in California through his admitted strategy of promoting a fictional “loop” dream as an alternative
3. He now advocates for privatizing American rail – despite the fact that no fully privatized passenger rail system in the world has achieved anything close to China’s success

This isn’t just inconsistency – it’s a deliberate strategy that has helped keep America decades behind global leaders in passenger rail.

The evidence against privatization as a solution for passenger rail is overwhelming. Every successful high-speed rail system in the world relies heavily on government investment, planning, and often operation:

• China: 100% state-owned and operated
• Japan: Built by the state, now operates through heavily regulated private companies that still rely on government support
• France: State-owned SNCF built and operates the TGV network
• Germany: Deutsche Bahn remains majority government-owned
• Spain: RENFE is a state-owned operator that runs the second-largest high-speed network
• South Korea: KORAIL is the government-owned operator of the successful KTX service

Even the United Kingdom’s experiment with rail privatization has been largely reversed, with infrastructure returned to public ownership under Network Rail after the failed experiment with private infrastructure company Railtrack.

There is not a single example worldwide of a successful fully-privatized high-speed rail system built from scratch without massive government investment and ongoing support.

The Dangerously Dumb New Proposal: Doubling Down on Failure

Musk’s recent comment that privatized entities create a “feedback loop for improvement” through the threat of bankruptcy ignores the fundamental nature of rail infrastructure. Passenger rail systems are natural monopolies that require massive upfront capital investment, serve public needs beyond profit maximization, and create value through network effects that aren’t captured on balance sheets.

His latest proposals for American rail are even more destructive than the Hyperloop distraction. Advocating for the wholesale privatization of Amtrak would likely result in:

1. Cherry-picking profitable routes: Private operators would focus exclusively on the Northeast Corridor while abandoning service to smaller cities and rural areas
2. Higher fares with less service: Without public service obligations, operators would maximize profit through premium pricing rather than expanding ridership
3. Infrastructure deterioration: For-profit entities have historically underinvested in long-term infrastructure maintenance when quarterly profits are at stake
4. Loss of network benefits: Fragmented private operators would create disconnected systems rather than the unified national network that China has proven works best

When essential transportation infrastructure faces bankruptcy, the public typically bears the cost anyway through bailouts or service disruptions that damage economic productivity. The “discipline of the market” that Musk touts rarely works as advertised in these contexts.

Ironically, China’s approach has been exactly the opposite of what Musk proposes. China recognized that only massive, coordinated state investment could create a comprehensive national network. Their centralized planning allowed them to standardize technology, ensure interoperability, and build complementary urban transit systems that feed into the high-speed network.

The pattern is clear: After helping to kill America’s best attempt to build something like China’s successful state-run system, Musk now praises that system while pushing privatization schemes that have failed everywhere they’ve been tried.

China Proves Musk a Liar: What Actually Works

China’s rail miracle offers the clearest evidence contradicting Musk’s privatization fantasy. In just 15 years, China has built over 40,000 kilometers of high-speed rail – more than the rest of the world combined – using an approach that is the direct opposite of what Musk advocates:

1. 100% state ownership and operation: China’s entire high-speed rail system is owned and operated by China State Railway Group Co., Ltd., a state-owned enterprise
2. Massive public investment: China has invested over $1 trillion in its high-speed rail network, recognizing that the economic and social returns justify the public expenditure
3. Long-term planning: China developed comprehensive 15-year plans for its national network and stuck with them, rather than chasing private-sector fads or allowing short-term politics to derail progress
4. Integrated systems: China’s rail network is designed as a unified system with standardized technology, consistent user experience, and seamless connections to local transit
5. Land use coordination: New high-speed rail stations anchor transit-oriented development, maximizing both ridership and economic benefits

The results speak for themselves. China now has the world’s most extensive, most used, and in many ways most advanced passenger rail system. It has transformed the nation’s economy by connecting previously distant regions into unified economic zones and providing sustainable transportation for hundreds of millions of people.

This success came not through privatization but through the exact kind of government-led initiative that Musk helped undermine in California and now argues against while simultaneously praising its results.

Systematic Fraud Against American Infrastructure

The evidence is overwhelming and the contradiction damning: Musk deliberately sabotaged America’s best attempt to create a state-run high-speed rail system comparable to China’s through what can only be described as a fraudulent Hyperloop scheme. Now he praises China’s state-run system while advocating for a privatization model that has demonstrably failed everywhere it’s been attempted.

This isn’t mere hypocrisy—it represents a pattern of deception that has done measurable harm to America’s transportation future. By promoting Hyperloop vaporware to undermine California’s high-speed rail and now pushing failed privatization models, Musk has twice worked to prevent America from developing the kind of rail system he himself acknowledges is superior when he sees it in China.

America doesn’t need transportation opportunists promoting fraudulent “solutions” that consistently benefit their own interests while undermining critical public infrastructure, gutting the country.

We need the political courage to turn away from snake-oil and invest in what actually works—government-backed, strategically planned rail networks like China’s—and to recognize when empty technological promises are deliberate fraud tactics to derail genuine progress.