CVE-2007-3731

Severity: medium (CVSS 4.9 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.5% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2007-09-17 · updated 2026-06-16
Weakness: CWE-20

Description

The Linux kernel 2.6.20 and 2.6.21 does not properly handle an invalid LDT segment selector in %cs (the xcs field) during ptrace single-step operations, which allows local users to cause a denial of service (NULL dereference and OOPS) via certain code that makes ptrace PTRACE_SETREGS and PTRACE_SINGLESTEP requests, related to the TRACE_IRQS_ON function, and possibly related to the arch_ptrace function.

Affected products

Linux kernel: 2.6.20, 2.6.21

References

http://bugzilla.kernel.org/show_bug.cgi?id=8765
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=29eb51101c02df517ca64ec472d7501127ad1da8
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=a10d9a71bafd3a283da240d2868e71346d2aef6f
http://osvdb.org/37286
http://secunia.com/advisories/26935
http://secunia.com/advisories/26955
http://secunia.com/advisories/26978
http://secunia.com/advisories/27322
http://secunia.com/advisories/29159
http://wiki.rpath.com/wiki/Advisories:rPSA-2008-0094
http://www.debian.org/security/2007/dsa-1378
http://www.redhat.com/support/errata/RHSA-2007-0940.html

Get alerted when CVE-2007-3731 or the next vulnerability affects your stack