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Vulnerability record · CVE-2005-0021 · published 2 May 2005

CVE-2005-0021: University of cambridge exim vulnerability

University Of Cambridge · Exim

Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 components, as demonstrated using the -be command line option, which triggers an overflow in the host_aton function, or (2) the -bh command line option or dnsdb PTR lookup, which triggers an overflow in the dns_build_reverse function.

7.2 CVSS 2.0 High EPSS 2.6% · top 15.2%
7.2CVSS 2.0 base score
2.6%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
20References, 2 tagged exploit
16 Jun 2026Last modified by NVD

Description

Multiple buffer overflows in Exim before 4.43 may allow attackers to execute arbitrary code via (1) an IPv6 address with more than 8 components, as demonstrated using the -be command line option, which triggers an overflow in the host_aton function, or (2) the -bh command line option or dnsdb PTR lookup, which triggers an overflow in the dns_build_reverse function.

AV:L/AC:L/Au:N/C:C/I:C/A:C

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
http://security.gentoo.org/glsa/glsa-200501-23.xml Vendor Advisory
http://www.debian.org/security/2005/dsa-635 Vendor Advisory
http://www.debian.org/security/2005/dsa-637 Vendor Advisory
http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
http://www.idefense.com/application/poi/display?id=179&type=vulnerabilities Vendor Advisory
http://www.idefense.com/application/poi/display?id=183&type=vulnerabilities ExploitVendor Advisory
http://www.kb.cert.org/vuls/id/132992 PatchUS Government Resource
http://www.redhat.com/support/errata/RHSA-2005-025.html Patch
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10347
http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
http://security.gentoo.org/glsa/glsa-200501-23.xml Vendor Advisory
http://www.debian.org/security/2005/dsa-635 Vendor Advisory
http://www.debian.org/security/2005/dsa-637 Vendor Advisory
http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
http://www.idefense.com/application/poi/display?id=179&type=vulnerabilities Vendor Advisory
http://www.idefense.com/application/poi/display?id=183&type=vulnerabilities ExploitVendor Advisory
http://www.kb.cert.org/vuls/id/132992 PatchUS Government Resource
http://www.redhat.com/support/errata/RHSA-2005-025.html Patch
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10347

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Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2005-0021), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.