Description
Heap-based buffer overflow in the dkim_exim_query_dns_txt function in dkim.c in Exim 4.70 through 4.80, when DKIM support is enabled and acl_smtp_connect and acl_smtp_rcpt are not set to "warn control = dkim_disable_verify," allows remote attackers to execute arbitrary code via an email from a malicious DNS server.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | exim4 | 4.80-5.1 | — |
| Debian 13 | exim4 | 4.80-5.1 | — |
| Debian 12 | exim4 | 4.80-5.1 | — |
| Debian 6.0 | exim4 | 4.72-6+squeeze3 | DSA-2566-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | exim | 4.86.2-2.2 | openSUSE-SU-2024:10017-1 |
Advisories 2
- DSA-2566-1 exim4 - heap overflow Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2024:10017-1 exim-4.86.2-2.2 on GA media SUSE / openSUSE Security Updates · May 7, 2025
References
- 51115 third-party-advisory
- [oss-security] 20121027 CVE-2012-5671: Exim <= 4.80 DKIM heap-based buffer overflow mailing-list
- 51155 third-party-advisory
- [exim-announce] 20121026 Exim 4.80.1 Security Release mailing-list
- USN-1618-1 vendor-advisory
- 51098 third-party-advisory
- FEDORA-2012-17044 vendor-advisory
- FEDORA-2012-17085 vendor-advisory
- 51153 third-party-advisory
- 86616 vdb-entry
- openSUSE-SU-2012:1404 vendor-advisory
- 56285 vdb-entry
- exim-dkimeximquerydnstxt-bo(79615) vdb-entry
- FEDORA-2012-16899 vendor-advisory
- DSA-2566 vendor-advisory