Description
Buffer overflow in the spa_base64_to_bits function in Exim before 4.43, as originally obtained from Samba code, and as called by the auth_spa_client function, may allow attackers to execute arbitrary code during SPA authentication.
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 | 4.34-10 | — |
| Debian 13 | exim4 | 4.34-10 | — |
| Debian 12 | exim4 | 4.34-10 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 4 | exim +3 | 4.43-1.RHEL4.3 | RHSA-2005:025 |
Advisories 1
- RHSA-2005:025 Red Hat Security Advisory: exim security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
References
- oval:org.mitre.oval:def:11293 vdb-entry signature
- http://ftp6.us.freebsd.org/pub/mail/exim/ChangeLogs/ChangeLog-4.44
- 20050212 exim auth_spa_server() PoC exploit mailing-list
- 12188 vdb-entry
- RHSA-2005:025 vendor-advisory
- 20050107 Exim auth_spa_server() Buffer Overflow Vulnerability third-party-advisory
- GLSA-200501-23 vendor-advisory
- [exim] 20050104 2 smallish security issues mailing-list