CVE catalog

CVE-2020-14002

putty: CVE-2020-14002

Severity: Medium
Published: Jun 29, 2020, 6:15:00 PM UTC
Source: [NVD] · [CVE record]
EPSS: 3.13% · Oct 25, 2026

PuTTY 0.68 through 0.73 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client).

Vulnerable and fixed packages

Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.

Distribution	Package	Release	Version	Status
Debian	putty	sid	`0.85-3`	fixed
Debian	putty	forky	`0.85-3`	fixed
Debian	putty	trixie	`0.83-3`	fixed
Debian	putty	bookworm	`0.78-2+deb12u2`	fixed
Debian	putty	bookworm-security	`0.78-2+deb12u1`	fixed
Alpine	putty	3.10	`0.74-r0`	fixed
Alpine	putty	3.11	`0.74-r0`	fixed
Alpine	putty	3.12	`0.74-r0`	fixed
Alpine	putty	3.13	`0.74-r0`	fixed
Alpine	putty	3.14	`0.74-r0`	fixed
Alpine	putty	3.15	`0.74-r0`	fixed
Alpine	putty	3.16	`0.74-r0`	fixed
Alpine	putty	3.17	`0.74-r0`	fixed
Alpine	putty	3.18	`0.74-r0`	fixed
Alpine	putty	3.19	`0.74-r0`	fixed
Alpine	putty	3.9	`0.74-r0`	fixed
Ubuntu	putty	16.04	`0.65-2`	vulnerable
Ubuntu	putty	16.04	`0.66-1`	vulnerable
Ubuntu	putty	16.04	`0.66-2`	vulnerable
Ubuntu	putty	16.04	`0.66-3`	vulnerable
Ubuntu	putty	16.04	`0.66-4`	vulnerable
Ubuntu	putty	16.04	`0.67-1`	vulnerable
Ubuntu	putty	16.04	`0.67-2`	vulnerable
Ubuntu	putty	16.04	`0.67-3build0.16.04.1`	vulnerable
Ubuntu	putty	16.04	`0.67-3+deb9u1build0.16.04.1`	vulnerable
Ubuntu	putty	18.04	`0.70-1`	vulnerable
Ubuntu	putty	18.04	`0.70-2`	vulnerable
Ubuntu	putty	18.04	`0.70-3`	vulnerable
Ubuntu	putty	18.04	`0.70-4`	vulnerable
Ubuntu	putty	20.04	`0.72-1`	vulnerable
Ubuntu	putty	20.04	`0.73-1`	vulnerable
Ubuntu	putty	20.04	`0.73-2`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	putty	source	sid	`0.74-1`	not yet assigned	Not reported	Not reported
Debian	putty	source	forky	`0.74-1`	not yet assigned	Not reported	Not reported
Debian	putty	source	trixie	`0.74-1`	not yet assigned	Not reported	Not reported
Debian	putty	source	bookworm	`0.74-1`	not yet assigned	Not reported	Not reported
Alpine	putty	apk	3.10	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.11	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.12	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.13	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.14	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.15	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.16	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.17	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.18	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.19	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported
Alpine	putty	apk	3.9	`0.74-r0`	Not reported	ALPINE-CVE-2020-14002	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[pterm]Fixed
Source package: [putty]
Details (4)
- 0.78-2+deb12u2 · amd64 · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u2 · arm64 · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · amd64 · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · arm64 · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
[putty]Fixed
Details (4)
- 0.78-2+deb12u2 · amd64 · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u2 · arm64 · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · amd64 · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · arm64 · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
[putty-doc]Fixed
Source package: [putty]
Details (4)
- 0.78-2+deb12u2 · all · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u2 · all · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · all · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · all · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
[putty-tools]Fixed
Source package: [putty]
Details (4)
- 0.78-2+deb12u2 · amd64 · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u2 · arm64 · bookworm
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · amd64 · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12
- 0.78-2+deb12u1 · arm64 · bookworm-security
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · bookworm; dsa · putty · debian · 12

[Debian 13 (Trixie)]

[pterm]Fixed
Source package: [putty]
Details (2)
- 0.83-3 · amd64 · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
- 0.83-3 · arm64 · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
[putty]Fixed
Details (2)
- 0.83-3 · amd64 · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
- 0.83-3 · arm64 · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
[putty-doc]Fixed
Source package: [putty]
Details (2)
- 0.83-3 · all · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
- 0.83-3 · all · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
[putty-tools]Fixed
Source package: [putty]
Details (2)
- 0.83-3 · amd64 · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13
- 0.83-3 · arm64 · trixie
  Fixed · Fixed: 0.74-1
  dsa · putty · debian · 13

Observed: Oct 23, 2026, 5:47:45 PM UTC

References

[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]