CVE-2021-36367

low
Published — · Modified —
CVSS v3
CVSS v4 NEW
not yet in upstream
VIR risk
2.5

Description

PuTTY through 0.75 proceeds with establishing an SSH session even if it has never sent a substantive authentication response. This makes it easier for an attacker-controlled SSH server to present a later spoofed authentication prompt (that the attacker can use to capture credential data, and use that data for purposes that are undesired by the client user).

Predictions

Exploit likelihood
20%
Patch ETA

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

arch Arch Fixed 1 release
VersionStatusFixed in
Fixed 0.76-1
debian Debian Fixed 5 releases
VersionStatusFixed in
trixie Fixed 0.75-3
sid Fixed 0.75-3
forky Fixed 0.75-3
bullseye Fixed 0.74-1+deb11u1
bookworm Fixed 0.75-3

References

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

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