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.
CVE-2005-0021
- No confirmed exploitation signals yet
A fix is available — apply it.
- CVSS v3
- —
- EG Score
- 0.0(none)
- EPSS
- 83.6%
- KEV
- Not listed
Published
May 2, 2005
Last Modified
June 16, 2026
References (20)
- cve@mitrehttp://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
- cve@mitrehttp://security.gentoo.org/glsa/glsa-200501-23.xml
- cve@mitrehttp://www.debian.org/security/2005/dsa-635
- cve@mitrehttp://www.debian.org/security/2005/dsa-637
- cve@mitrehttp://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
- cve@mitrehttp://www.idefense.com/application/poi/display?id=179&type=vulnerabilities
- cve@mitrehttp://www.idefense.com/application/poi/display?id=183&type=vulnerabilities
- cve@mitrehttp://www.kb.cert.org/vuls/id/132992
- cve@mitrehttp://www.redhat.com/support/errata/RHSA-2005-025.html
- cve@mitrehttps://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10347
- af854a3a-2127-422b-91ae-364da2661108http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
- af854a3a-2127-422b-91ae-364da2661108http://security.gentoo.org/glsa/glsa-200501-23.xml
- af854a3a-2127-422b-91ae-364da2661108http://www.debian.org/security/2005/dsa-635
- af854a3a-2127-422b-91ae-364da2661108http://www.debian.org/security/2005/dsa-637
- af854a3a-2127-422b-91ae-364da2661108http://www.exim.org/mail-archives/exim-users/Week-of-Mon-20050103/msg00028.html
Patch Availability(2)
| Vendor / Ecosystem | Fixed in / Patch | Released | Source |
|---|---|---|---|
| ubuntu | exim4-daemon-light () @ warty | 2026-05-31 | ubuntu |
| redhat | exim-0:4.43-1.RHEL4.3 | 2005-02-15 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
All Vendor Advisories
(2)
Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.
Data Freshness Timeline
(refreshed 6× in last 7d / 28× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-13 06:07 UTCEPSS rescore
- 2026-07-13 06:07 UTCEPSS rescore
- 2026-07-11 08:22 UTCEPSS rescore
- 2026-07-11 08:22 UTCEPSS rescore
- 2026-07-09 05:39 UTCOSV refresh
- 2026-07-08 15:09 UTCEPSS rescore
- 2026-07-06 02:19 UTCEPSS rescore
- 2026-07-06 02:19 UTCEPSS rescore
- 2026-07-02 14:00 UTCEPSS rescore
- 2026-07-01 15:01 UTCEPSS rescore
- 2026-06-28 04:52 UTCEPSS rescore
- 2026-06-27 03:04 UTCEPSS rescore
- 2026-06-25 13:46 UTCEPSS rescore
- 2026-06-24 14:01 UTCEPSS rescore
- 2026-06-23 21:29 UTCEPSS rescore
- 2026-06-21 01:56 UTCEPSS rescore
- 2026-06-20 17:42 UTCOSV refresh
- 2026-06-19 19:22 UTCEPSS rescore
- 2026-06-18 17:49 UTCEPSS rescore
- 2026-06-18 17:49 UTCEPSS rescore
- 2026-06-17 17:49 UTCEPSS rescore
- 2026-06-17 17:49 UTCEPSS rescore
- 2026-06-16 17:49 UTCEPSS rescore
- 2026-06-16 17:49 UTCEPSS rescore
- 2026-06-15 17:44 UTCEPSS rescore
Show 44 moreShow fewer
- 2026-06-14 23:13 UTCEPSS rescore
- 2026-06-14 23:13 UTCEPSS rescore
- 2026-06-13 22:56 UTCEPSS rescore
- 2026-06-12 23:08 UTCEPSS rescore
- 2026-06-11 13:55 UTCEPSS rescore
- 2026-06-10 22:14 UTCEPSS rescore
- 2026-06-10 13:17 UTCEPSS rescore
- 2026-06-08 14:13 UTCEPSS rescore
- 2026-06-07 15:21 UTCEPSS rescore
- 2026-06-06 13:44 UTCEPSS rescore
- 2026-06-06 13:44 UTCEPSS rescore
- 2026-06-05 22:43 UTCEPSS rescore
- 2026-06-05 22:43 UTCEPSS rescore
- 2026-06-05 06:07 UTCEPSS rescore
- 2026-06-05 06:07 UTCEPSS rescore
- 2026-06-04 13:09 UTCEPSS rescore
- 2026-06-04 13:09 UTCEPSS rescore
- 2026-06-02 20:10 UTCEPSS rescore
- 2026-06-02 20:10 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-06-01 13:49 UTCEPSS rescore
- 2026-05-31 22:28 UTCEPSS rescore
- 2026-05-31 13:25 UTCEG score recompute
- 2026-05-31 13:25 UTCVendor advisory
- 2026-05-31 13:25 UTCGHSA enrichment
- 2026-05-31 00:13 UTCEPSS rescore
- 2026-05-31 00:13 UTCEPSS rescore
- 2026-05-29 13:40 UTCEPSS rescore
- 2026-05-29 13:40 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-27 13:37 UTCEPSS rescore
- 2026-05-26 07:16 UTCEPSS rescore
- 2026-05-26 07:16 UTCEPSS rescore
- 2026-05-24 16:42 UTCEPSS rescore
- 2026-05-22 21:15 UTCEPSS rescore
- 2026-05-22 09:26 UTCOSV refresh
- 2026-05-21 22:38 UTCEPSS rescore
- 2026-05-20 22:36 UTCEPSS rescore
- 2026-05-20 22:36 UTCEPSS rescore
- 2026-05-20 11:20 UTCEPSS rescore
- 2026-05-20 11:20 UTCEPSS rescore
- 2026-05-18 21:29 UTCEPSS rescore
Publicly available exploits
(2 references)Working exploit code is in the public domain (2 Exploit-DB entries). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-1009✓ verifiedFirst seen May 25, 2005
Exim 4.41 - 'dns_build_reverse' Local Read Emails
Open source ↗ - Exploit-DBEDB-756✓ verifiedFirst seen Jan 15, 2005
Exim 4.41 - 'dns_build_reverse' Local Buffer Overflow
Open source ↗
Frequently asked(4)
What is CVE-2005-0021?
When was CVE-2005-0021 disclosed?
Is CVE-2005-0021 actively exploited?
How do I remediate CVE-2005-0021?
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