CVE-2022-3559: Exim Regex use after free

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 5.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-10-17 · updated 2026-06-17
Weakness: CWE-119

Description

A vulnerability was found in Exim and classified as problematic. This issue affects some unknown processing of the component Regex Handler. The manipulation leads to use after free. The name of the patch is 4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2. It is recommended to apply a patch to fix this issue. The identifier VDB-211073 was assigned to this vulnerability.

Affected products

Exim: before 4.97 — fixed in 4.97
Fedoraproject Fedora: 35, 36, 37

How to fix

Upgrade to a fixed version: Exim 4.97. Check the vendor advisory for mitigations.

References

https://bugs.exim.org/show_bug.cgi?id=2915
https://git.exim.org/exim.git/commit/4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EIH4W5R7SHTUEQFWWKB4TUO5YFZX64KV/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMQ6OCKPNPBPSD37YR4FOWV2R54M2UEP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFHLZVHNNO2GWYP5EA4TZQZ5O4GVPARR/
https://vuldb.com/?id.211073
https://bugs.exim.org/show_bug.cgi?id=2915
https://git.exim.org/exim.git/commit/4e9ed49f8f12eb331b29bd5b6dc3693c520fddc2
https://lists.debian.org/debian-lts-announce/2024/10/msg00029.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/EIH4W5R7SHTUEQFWWKB4TUO5YFZX64KV/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/TMQ6OCKPNPBPSD37YR4FOWV2R54M2UEP/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/WFHLZVHNNO2GWYP5EA4TZQZ5O4GVPARR/

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