CVE-2009-1243

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2009-04-06 · updated 2026-06-16
Weakness: CWE-667

Description

net/ipv4/udp.c in the Linux kernel before 2.6.29.1 performs an unlocking step in certain incorrect circumstances, which allows local users to cause a denial of service (panic) by reading zero bytes from the /proc/net/udp file and unspecified other files, related to the "udp seq_file infrastructure."

Affected products

Linux kernel: before 2.6.29.1 — fixed in 2.6.29.1

How to fix

Upgrade to a fixed version: Linux kernel 2.6.29.1. Check the vendor advisory for mitigations.

References

http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=30842f2989aacfaba3ccb39829b3417be9313dbe
http://openwall.com/lists/oss-security/2009/04/01/4
http://secunia.com/advisories/34478
http://vigilance.fr/vulnerability/Linux-kernel-denial-of-service-via-proc-net-udp-8586
http://www.kernel.org/pub/linux/kernel/v2.6/ChangeLog-2.6.29.1
http://www.securityfocus.com/bid/34329
http://www.vupen.com/english/advisories/2009/0924
https://exchange.xforce.ibmcloud.com/vulnerabilities/49595
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commit%3Bh=30842f2989aacfaba3ccb39829b3417be9313dbe
http://openwall.com/lists/oss-security/2009/04/01/4
http://secunia.com/advisories/34478
http://vigilance.fr/vulnerability/Linux-kernel-denial-of-service-via-proc-net-udp-8586

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