CVE-2021-36367: 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…

PriorityP345high8.1CVSS 3.1

AVNACLPRNUIRSUCHIHAN

EPSS

1.11%

62.0th percentile

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).

Affected

6 ranges

Vendor	Product	Version range	Fixed in
debian	putty	< putty 0.75-3 (bookworm)	putty 0.75-3 (bookworm)
putty	putty	<= 0.75	—
putty	putty	>= 0 < 0.74-1+deb11u1	0.74-1+deb11u1
putty	putty	>= 0 < 0.75-3	0.75-3
putty	putty	>= 0 < 0.75-3	0.75-3
putty	putty	>= 0 < 0.75-3	0.75-3

CVSS provenance

nvdv3.18.1HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N

nvdv2.05.8MEDIUMAV:N/AC:M/Au:N/C:P/I:P/A:N

osv8.1HIGH

vendor_debian8.1HIGH

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