CVE-2024-43882

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

exec: Fix ToCToU between perm check and set-uid/gid usage

When opening a file for exec via do_filp_open(), permission checking is

done against the file's metadata at that moment, and on success, a file

pointer is passed back. Much later in the execve() code path, the file

metadata (specifically mode, uid, and gid) is used to determine if/how

to set the uid and gid. However, those values may have changed since the

permissions check, meaning the execution may gain unintended privileges.

For example, if a file could change permissions from executable and not

set-id:

---------x 1 root root 16048 Aug 7 13:16 target

to set-id and non-executable:

---S------ 1 root root 16048 Aug 7 13:16 target

it is possible to gain root privileges when execution should have been

disallowed.

While this race condition is rare in real-world scenarios, it has been

observed (and proven exploitable) when package managers are updating

the

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References