CVE-2010-2023

Severity: medium (CVSS 4.4 v2.0)
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: 2010-06-07 · updated 2026-06-16
Weakness: CWE-362

Description

transports/appendfile.c in Exim before 4.72, when a world-writable sticky-bit mail directory is used, does not verify the st_nlink field of mailbox files, which allows local users to cause a denial of service or possibly gain privileges by creating a hard link to another user's file.

Affected products

Exim: through 4.71; 4.10, 4.20, 4.21, 4.22, 4.23, 4.24 (+26)

References

http://archives.neohapsis.com/archives/fulldisclosure/2010-06/0079.html
http://bugs.exim.org/show_bug.cgi?id=988
http://lists.exim.org/lurker/message/20100524.175925.9a69f755.en.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-June/042587.html
http://lists.fedoraproject.org/pipermail/package-announce/2010-June/042613.html
http://lists.opensuse.org/opensuse-security-announce/2010-08/msg00001.html
http://secunia.com/advisories/40019
http://secunia.com/advisories/40123
http://secunia.com/advisories/43243
http://vcs.exim.org/viewvc/exim/exim-doc/doc-txt/ChangeLog?view=markup&pathrev=exim-4_72_RC2
http://vcs.exim.org/viewvc/exim/exim-src/src/transports/appendfile.c?r1=1.24&r2=1.25
http://www.securityfocus.com/archive/1/511653/100/0/threaded

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