#VU2597 Path traversal in Linux kernel - CVE-2015-2925

Vulnerability identifier: #VU2597

Vulnerability risk: Low

CVSSv4.0: 5.9 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2015-2925

CWE-ID: CWE-22

Exploitation vector: Local

Exploit availability: No

Vulnerable software:
Linux kernel
Operating systems & Components / Operating system

Vendor: Linux Foundation

Description
The vulnerability allows a local attacker to gain elevated privileges on the target system.

The weakness exists in the prepend_path function in fs/dcache.c due to improper handling of rename actions inside a bind mount. A local attacker can bypass an intended container protection mechanism by renaming a directory, related to a "double-chroot attack" and gain root privileges.

Mitigation
Update to version 4.2.4.

Vulnerable software versions

Linux kernel: 4.2.0 - 4.2.3

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External links
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=cde93be45a8a90d8c264c776fab63487b5038a65

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Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.