CVE-2023-51766

unknown

Published — · Modified —

💬 Discuss on Community ✚ Propose mitigation

CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

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Description

Exim before 4.97.1 allows SMTP smuggling in certain PIPELINING/CHUNKING configurations. Remote attackers can use a published exploitation technique to inject e-mail messages with a spoofed MAIL FROM address, allowing bypass of an SPF protection mechanism. This occurs because Exim supports <LF>.<CR><LF> but some other popular e-mail servers do not.

Predictions

Exploit likelihood

20%

Patch ETA

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Heuristic predictions, AS-IS, for prioritization only.

Mitigations

No mitigations published for this CVE yet.

The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.

✚ Propose a mitigation on Community → Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here with source_tier=community-verified.

OS impact

OS	Version	Status	Fixed in
debian	bookworm	fixed	`4.96-15+deb12u4`
debian	bullseye	fixed	`4.94.2-7+deb11u2`
debian	forky	fixed	`4.97-3`
debian	sid	fixed	`4.97-3`
debian	trixie	fixed	`4.97-3`

References

https://security-tracker.debian.org/tracker/CVE-2023-51766

Community-verified mitigations for this CVE will appear above when contributors publish them.

Verify integrity in audit chain (admin only). AS-IS.