Vulnerability in BIOS being used to gain access
Vulnerability in BIOS being used to gain access
They remain uncertain about potential risks such as unauthorized access to your financial data or keylogging activities. Regardless of their intentions, LogoFail provides the capability to carry out various harmful actions. In theory—though its feasibility is unclear—they might deploy a virtual machine before the BIOS performs security checks, isolating their operations and allowing full monitoring. If the attack occurs remotely, it likely relies on browser vulnerabilities. Most browsers are sandboxed, yet experts regularly demonstrate ways to bypass these protections. Social engineering remains a common tactic (e.g., phishing emails or compromised accounts), and physical access could also be exploited, such as through a rogue device like a rubber ducky.
If on-site, they might not need to breach security unless they can directly interact with the system. In that case, simple methods like physical insertion could work.
The discussion clarifies misconceptions about BIOS compromise, emphasizing that vulnerabilities exist independently of BIOS state. No need to install malicious updates or purchase compromised software. The issues persist due to longstanding flaws in UEFI systems.
Replacing firmware isn’t the only solution—addressing the root vulnerabilities is essential. Recent updates should have been released, but awareness of these persistent risks remains crucial.
Unfortunately, neither ASUS nor AMI have taken any action regarding this.
But if the first vulnerability - remember that it that allowed them to place the image in ESP, which requires adm permissions to begin with - already allows them to do so, what different would LogoFail do? Not doable. This doesn't suddenly give you administrator access to place stuff in the ESP. Still requires administrator access, and the major issue is that first vulnerability that happen, then payload (be either logofail or something else) seems somewhat irrelevant, since you could just make the victim install a dumb keylogger at this point too. Still requires administrator access. And physical access is already a compromise, logofail should be the least of your worries. They don't put any firmware, this is a code execution vulnerability. The original firmware parses the custom image, and the custom image has malicious code that does other stuff. The custom image has to be in the ESP to be loaded, so there's only 2 possible ways for this to happen: 1- Either the user does that by being tricked somehow, or by their device already being compromised by another piece of software that does this (which goes back to the top of my post) 2- The image came in there already out of the box or within the firmware already. On the original blog post about the issue, they even discussed that one way this may happen is by hacking the bios updater from one of the vendors. Clearing out the ESP solves the issue, that's it, nothing more. Reinstall windows or linux and your ESP gets formatted, it's just a regular FAT32 partition containing the .EFI file for your bootloader. oh, just saw it in the original blog too (I hadn't read it before fwiw), thanks.
LogoFAIL represents the 12 weaknesses in UEFI BIOS that let attackers exploit them via a compromised logo. When the parser reads the logo details, it runs the code and inserts it into the firmware. You don’t need it—hackers already bypassed OS and BIOS defenses. If you want deeper access to plant these changes, it’s possible. Major cybersecurity events like Pwn2Own and DefCon repeatedly demonstrate this, even with strong browser protections. I don’t fully grasp the technical details—I’m still learning about cybersecurity. For more insights, check Darknet Diaries on Apple or YouTube, or visit BleepingComputer.com for recent reports. Remember, controlling the firmware is key; if you manage it, malware won’t detect your intrusion since it operates outside the system’s normal boundaries. It resides in firmware, memory, and storage, giving it persistence and full access. No. I’ve covered other attack vectors—full protection isn’t achievable unless you disable the system constantly. A zero-day exploit from email, a website, or a direct breach can deliver payloads. The article notes that simply removing ESP doesn’t eliminate the threat, as the infected logo remains a program, not just an image. Its executable code runs because of a vulnerability. NP. See the original Binarly video and blog for more context.
No, that's not how it works from what I understood. The order from my understanding is as follow: 0- Attacker manages to have administrator access to the device 1- Malicious logo gets placed in the ESP 2- UEFI ENV VAR gets set so the UEFI firmware tries to parse this logo 3- During boot, the UEFI firmware tries to parse that image, does a bad job at it, generating a arbitrary code execution 4- Your malicious payload is free to do anything at will In their own demo video was how that worked, they needed to have adm access before writing the malicious image into the ESP. You do, watch their demo. Yes, I'm referring to that. If you already managed to elevate your access and run code that places a piece of data in the boot partition, you could do anything else, that's my point. Binarly did an announcement without explanation 8 days ago, but the embargo only lifted yesterday, I guess that's why you have those dates for those publications. I didn't read any of those, just the actual blog post from the ones that found out the vulnerability. You don't control the firmware, period. It's not outside the system! It can do stuff before the system starts, like placing a file somewhere (as in their demo), modifying init scripts and whatnot, but it doesn't keep running after your system boots. It can be used to trigger another piece of software after your system boots, the issue is that, even if your AV tool detects it, by the next reboot the exploit is going to place the files in there again until you remove it from the ESP. It's not in the firmware, it gets loaded by the firmware, that's a different thing. It has access to storage and memory during its execution, but no access to any of those after the OS is up and running. It has no persistence, but does have full disk access BEFORE the OS starts (which allows you to setup many different things). Ok, just to try to make it clear again, imagefail is one of those payloads. For it to be dropped, you need to be infected in other way, which means you already got compromised beforehand, if the payload is that exploit it's kinda moot since you've been already breached. In the binarly article this is not mentioned at all. It's a file in the ESP, of course you can delete it, and then the UEFI won't have anything to load. You won't get rid of the vulnerability itself, since it's a bug in the firmware, but the actual malicious payload can simply be deleted (but nothing stops you falling into a future exploit and having a new malicious file placed in there again). You do, the infected logo is a literal file in the ESP. It's an image with extra trailing data, that once the firmware goes out of bounds reading it, can be executed as a program. Yes, it there's no executable code to run, the vulnerable parser won't have anything to run, hence nothing will happen.
It has been a bit tough for me, but I believe I grasp what you meant with your earlier remarks. You were referring to a tampered firmware from the factory or through an update, which is the only way—though not universal, since most systems guard against such changes. The rare cases where BIOS allows logo customization are unclear to me. Your focus also included physical attacks on weak systems; I’m still figuring out the details, possibly because I haven’t studied this deeply or am simply not familiar with EFI/ESP. I agree with your ordered points. This approach is more subtle than inserting a malicious bootkit directly into the ESP. It suggests that high-level formats won’t fully remove the logo, while low-level ones might. My comments about reinstalling or reformatting not working were based on ArsTechnica’s explanation: even with protections against writing to the ESP, another method remains. My views on resetting Windows/Linux or reformatting being ineffective came from their statement, which I now see as pointing out that bypassing protections is significantly more effective than hiding malware inside the OS. Listening to hacker stories on Darknet Diaries shows how slowly they must move to avoid detection. With a BIOS-level exploit, this issue seems less pressing, though total invisibility isn’t guaranteed. I realize now that standing in the middle of all defenses is less effective than finding a place where they can’t see you. I only saw the content from six days ago (the video and blog), and 12/6. That’s better than before, as long as you understand. Some of what Binarly discussed goes beyond my current grasp. I see your point. Unless the scenarios involve firmware tampering, hackers don’t have full control. Still, even without full firmware authority, you retain significant influence over memory and storage—below the OS level—so modifications there can be changed. That was the key idea: this exploit lets actions happen outside the system, enabling OS takeover. How much more effective is it to operate in a less visible spot than directly confronting guards? Hmm, can you clarify that? I only encountered it about six days ago (video and blog). That’s better, as long as you grasp it. Some of what Binarly explained is beyond my understanding. I appreciate your clarification. I’m still learning, so keep correcting me if I miss anything.
Yes, that's the only feasible method for installation without needing user action or prior compromise. From my perspective, this is the typical way such vulnerabilities are exploited—by sending a custom file to the ESP and having the BIOS interpret it. It seems fairly common, as noted in Binarly's discussion: physical attacks can be carried out when the firmware’s custom section isn<|pad|>, allowing you to potentially overwrite the SPI flash with malicious code.
At this stage, it might be simpler to directly access the device or replace its storage media with something else, like a Raspberry Pi, to install your own image. The ESP is essentially just a FAT32 partition, and I’ll use a Linux system as an example.
For instance, with a 500MB partition holding the bootloader EFI files and kernel images, or a 100MB Windows partition containing the bootloader file, you can place a malicious file there. The BIOS will read it and proceed as intended. If you remove the original, a fresh format should erase it, though the BIOS remains open to further tampering.
Be cautious about reading articles with exaggerated warnings; they can be sensational. In reality, such attacks usually rely on downloading compromised BIOS tools or hijacked vendor sites. This approach can be part of a larger strategy, but it’s unlikely to spread via simple email spam.
For someone targeting you, this would require significant effort—possibly only viable if the victim is a high-value target. The examples you shared highlight how critical it is to keep storage unencrypted and avoid leaving persistent traces.
If you delete the file (via formatting), the risk diminishes, though a new BIOS update or OS reinstall might still be needed. A VM could work in theory, but it’s impractical for most users.
Outside of memory limitations, persistence depends on whether the code survives OS boot—so you need to act before the system loads. If the disk isn’t encrypted, you might attempt to modify startup behavior or inject payloads.
In practice, a clean reinstall is the safest way to remove such threats. Only specialized recovery methods or firmware tweaks could leave remnants, but they’re rare and complex.