CVE-2020-12783 — Exim through 4
Exim through 4.93 has an out-of-bounds read in the SPA authenticator that could result in SPA/NTLM authentication bypass in auths/spa.c and auths/auth-spa.c.
Published
2020-05-11T13:51:54.000Z
Last modified
2024-08-04T12:04:22.871Z
01What is this vulnerability?
Exim through 4.93 has an out-of-bounds read in the SPA authenticator that could result in SPA/NTLM authentication bypass in auths/spa.c and auths/auth-spa.c.
02Affected products
| Vendor | Product | Versions |
|---|
| n | a / n/a | n/a |
03Active exploitation status
Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.
04Recommended remediation
- Patch to a fixed version listed in the vendor advisory (see references below).
- Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
- Hunt historical logs for exploitation indicators — see Detection signatures below.
05Technical details
For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.
06Detection signatures
Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.
07Related CVEs
No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.
08Timeline
- Published: 2020-05-11T13:51:54.000Z
- Last modified: 2024-08-04T12:04:22.871Z
09References
- bugs.exim.org — https://bugs.exim.org/show_bug.cgi?id=2571
- git.exim.org — https://git.exim.org/exim.git/commit/57aa14b216432be381b6295c312065b2fd034f86
- git.exim.org — https://git.exim.org/exim.git/commit/a04174dc2a84ae1008c23b6a7109e7fa3fb7b8b0
- www.debian.org — https://www.debian.org/security/2020/dsa-4687
- lists.debian.org — https://lists.debian.org/debian-lts-announce/2020/05/msg00017.html
- usn.ubuntu.com — https://usn.ubuntu.com/4366-1/
- lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
- lists.fedoraproject.org — https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro…
- www.openwall.com — http://www.openwall.com/lists/oss-security/2021/05/04/7
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