CVE-2013-4247

Severity: high (CVSS 7.8 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2013-08-25 · updated 2026-06-16
Weakness: CWE-189

Description

Off-by-one error in the build_unc_path_to_root function in fs/cifs/connect.c in the Linux kernel before 3.9.6 allows remote attackers to cause a denial of service (memory corruption and system crash) via a DFS share mount operation that triggers use of an unexpected DFS referral name length.

Affected products

Linux kernel: from 3.8 before 3.9.6 — fixed in 3.9.6

How to fix

Upgrade to a fixed version: Linux kernel 3.9.6. Check the vendor advisory for mitigations.

References

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=1fc29bacedeabb278080e31bb9c1ecb49f143c3b
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.9.6
http://www.openwall.com/lists/oss-security/2013/08/14/10
https://bugzilla.redhat.com/show_bug.cgi?id=998401
https://github.com/torvalds/linux/commit/1fc29bacedeabb278080e31bb9c1ecb49f143c3b
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=1fc29bacedeabb278080e31bb9c1ecb49f143c3b
http://www.kernel.org/pub/linux/kernel/v3.x/ChangeLog-3.9.6
http://www.openwall.com/lists/oss-security/2013/08/14/10
https://bugzilla.redhat.com/show_bug.cgi?id=998401
https://github.com/torvalds/linux/commit/1fc29bacedeabb278080e31bb9c1ecb49f143c3b

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