CVE-2020-8794

critical

Published — · Modified —

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CVSS v3

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CVSS v4 NEW

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not yet in upstream

VIR risk

10.0

Description

OpenSMTPD before 6.6.4 allows remote code execution because of an out-of-bounds read in mta_io in mta_session.c for multi-line replies. Although this vulnerability affects the client side of OpenSMTPD, it is possible to attack a server because the server code launches the client code during bounce handling.

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.

Exploits

Public proof-of-concept code below. AS-IS, for defenders and authorised testing only.

Exploit-DB

EDB-48140 remote openbsd

Qualys Corporation · 2020-02-26

OpenSMTPD < 6.6.3p1 - Local Privilege Escalation + Remote Code Execution

Source code queued for fetch — refresh in a moment.

EDB-48185 local linux verified

Metasploit · 2020-03-09

OpenSMTPD - OOB Read Local Privilege Escalation (Metasploit)

Source code queued for fetch — refresh in a moment.

Metasploit modules

exploit_unix/local/opensmtpd_oob_read_lpe rank 200

OpenSMTPD OOB Read Local Privilege Escalation

Source fetch failed: fetch_error — view the original via the link above.

OS impact

Arch Fixed 1 release

Version	Status	Fixed in
—	Fixed	`6.6.4p1-1`

Debian Fixed 5 releases

Version	Status	Fixed in
trixie	Fixed	`6.6.4p1-1`
sid	Fixed	`6.6.4p1-1`
forky	Fixed	`6.6.4p1-1`
bullseye	Fixed	`6.6.4p1-1`
bookworm	Fixed	`6.6.4p1-1`

References

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

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