CVE-2002-2438

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 3.7% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-05-18 · updated 2026-06-16
Weakness: CWE-287

Description

TCP firewalls could be circumvented by sending a SYN Packets with other flags (like e.g. RST flag) set, which was not correctly discarded by the Linux TCP stack after firewalling.

Affected products

Linux kernel: before 2.4.20 — fixed in 2.4.20

How to fix

Upgrade to a fixed version: Linux kernel 2.4.20. Check the vendor advisory for mitigations.

References

http://www.openwall.com/lists/oss-security/2012/02/03/7
http://www.openwall.com/lists/oss-security/2012/05/29/8
http://www.openwall.com/lists/oss-security/2012/05/30/11
http://www.openwall.com/lists/oss-security/2012/05/30/12
http://www.openwall.com/lists/oss-security/2012/05/30/13
http://www.openwall.com/lists/oss-security/2012/05/30/2
http://www.openwall.com/lists/oss-security/2012/05/30/4
http://www.openwall.com/lists/oss-security/2012/05/30/8
http://www.openwall.com/lists/oss-security/2012/05/30/9
http://www.openwall.com/lists/oss-security/2012/05/31/3
http://www.openwall.com/lists/oss-security/2014/02/12/8
https://bugzilla.suse.com/show_bug.cgi?id=744994%2C

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