Actively exploited vulnerability
Linux Kernel: memory corruption flaw under attack
CVE-2022-0185 · Linux Kernel Heap-Based Buffer Overflow Vulnerability
What is affected
Linux Kernel is found on ordinary personal computers and phones, so this is not only a problem for companies. If you use it and have not updated since the fix was released, you are exposed.
Linux kernel contains a heap-based buffer overflow vulnerability in the legacy_parse_param function in the Filesystem Context functionality. This allows an attacker to open a filesystem that does not support the Filesystem Context API and ultimately escalate privileges.
What an attacker can do
This is a memory corruption flaw. It lets an attacker corrupt the program's memory by feeding it specially crafted content: a web page, a file or a network message. The result ranges from a crash to the attacker running their own code.
- How it is reached
- Needs access to the device or a file opened on it
- Access the attacker needs
- No account needed
- Does the victim have to do something?
- No, works without the victim doing anything
What to do
- Update Linux Kernel now. Open the update or "About" screen, install whatever is offered and restart the app or device, because the fix is not active until you do.
- Turn on automatic updates so the next fix arrives without you having to look for it.
- If your device is too old to receive this update, stop using the affected app for anything sensitive and plan a replacement.
Apply updates per vendor instructions or discontinue use of the product if updates are unavailable.
Vendor advisories and fixes
- git.kernel.orggit.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=722d94847de2
How urgent is it
CISA added this vulnerability to its Known Exploited Vulnerabilities catalogue on August 21, 2024, which means there is reliable evidence of attacks in the wild. US federal agencies must fix it by September 11, 2024, a deadline that has already passed. That deadline does not bind anyone else, but it shows how seriously the agency rates it.
The EPSS model estimates a 25% probability that this flaw will be exploited somewhere in the next 30 days. That is higher than 98% of all scored vulnerabilities.
Its CVSS severity score is 8.4 out of 10 (high), as recorded in the US National Vulnerability Database.
Technical description
A heap-based buffer overflow flaw was found in the way the legacy_parse_param function in the Filesystem Context functionality of the Linux kernel verified the supplied parameters length. An unprivileged (in case of unprivileged user namespaces enabled, otherwise needs namespaced CAP_SYS_ADMIN privilege) local user able to open a filesystem that does not support the Filesystem Context API (and thus fallbacks to legacy handling) could use this flaw to escalate their privileges on the system.