Vulnerability · Published Jul 9, 2021 · Assigned by mitre
CVE-2021-36367
High 8.1
In plain English
A high-severity insufficient verification of data authenticity in the putty package (Alpine). There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 66% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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).
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | putty | 0.76-r0 | ALPINE-CVE-2021-36367 |
| Alpine:v3.21 | putty | 0.76-r0 | ALPINE-CVE-2021-36367 |
| Alpine:v3.22 | putty | 0.76-r0 | ALPINE-CVE-2021-36367 |
| Alpine:v3.23 | putty | 0.76-r0 | ALPINE-CVE-2021-36367 |
| Alpine:v3.24 | putty | 0.76-r0 | ALPINE-CVE-2021-36367 |
| Debian:12 | putty | 0.75-3 | DEBIAN-CVE-2021-36367 |
| Debian:13 | putty | 0.75-3 | DEBIAN-CVE-2021-36367 |
| Debian:14 | putty | 0.75-3 | DEBIAN-CVE-2021-36367 |
| Ubuntu:22.04:LTS | putty | no fix listed | UBUNTU-CVE-2021-36367 |
Affected products (as reported)
Weakness: CWE-345 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N