CVE-2020-12783

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.6% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2020-05-11 · updated 2026-06-17
Weakness: CWE-125

Description

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.

Affected products

Canonical Ubuntu Linux: 14.04, 16.04, 18.04, 19.10, 20.04
Debian Linux: 8.0, 9.0, 10.0
Exim: through 4.93
Fedoraproject Fedora: 31, 32

References

http://www.openwall.com/lists/oss-security/2021/05/04/7
https://bugs.exim.org/show_bug.cgi?id=2571
https://git.exim.org/exim.git/commit/57aa14b216432be381b6295c312065b2fd034f86
https://git.exim.org/exim.git/commit/a04174dc2a84ae1008c23b6a7109e7fa3fb7b8b0
https://lists.debian.org/debian-lts-announce/2020/05/msg00017.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/F6IQQ2SERFUD4WMRSX6XYDNK7Q4GPT7Y/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/M7Z5UG6ZIG32V7M4PP3BCC65C27EWK7G/
https://usn.ubuntu.com/4366-1/
https://www.debian.org/security/2020/dsa-4687
http://www.openwall.com/lists/oss-security/2021/05/04/7
https://bugs.exim.org/show_bug.cgi?id=2571
https://git.exim.org/exim.git/commit/57aa14b216432be381b6295c312065b2fd034f86

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