CVE catalog

CVE-2020-36477

mbedtls: CVE-2020-36477

Severity: Medium
Published: Aug 23, 2021, 2:15:00 AM UTC
Source: [NVD] · [CVE record]
EPSS: 0.86% · Oct 25, 2026

An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to control that IP address, though).

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	mbedtls	sid	`3.6.7-3`	fixed
Debian	mbedtls	forky	`3.6.7-3`	fixed
Debian	mbedtls	trixie	`3.6.6-0.1~deb13u1`	fixed
Debian	mbedtls	bookworm	`2.28.3-1`	fixed
Ubuntu	mbedtls	16.04	`2.1.2-1`	vulnerable
Ubuntu	mbedtls	16.04	`2.2.0-1`	vulnerable
Ubuntu	mbedtls	16.04	`2.2.1-1`	vulnerable
Ubuntu	mbedtls	16.04	`2.2.1-2`	vulnerable
Ubuntu	mbedtls	16.04	`2.2.1-2ubuntu0.1`	vulnerable
Ubuntu	mbedtls	16.04	`2.2.1-2ubuntu0.2`	vulnerable
Ubuntu	mbedtls	16.04	`2.2.1-2ubuntu0.3`	vulnerable
Ubuntu	mbedtls	pro	`2.16.2-1`	vulnerable
Ubuntu	mbedtls	pro	`2.16.3-1`	vulnerable
Ubuntu	mbedtls	pro	`2.16.4-1ubuntu2`	vulnerable
Ubuntu	mbedtls	pro	`2.16.4-1ubuntu2+esm1`	vulnerable

Fixed-version evidence

Distribution	Package	Type	Release	Fixed version	Urgency	Origin	Bugs
Debian	mbedtls	source	sid	`2.28.0-0.3`	not yet assigned	Not reported	Not reported
Debian	mbedtls	source	forky	`2.28.0-0.3`	not yet assigned	Not reported	Not reported
Debian	mbedtls	source	trixie	`2.28.0-0.3`	not yet assigned	Not reported	Not reported
Debian	mbedtls	source	bookworm	`2.28.0-0.3`	not yet assigned	Not reported	Not reported

OpenFactory catalog packages

[Debian 12 (Bookworm)]

[libmbedcrypto7]Fixed
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
[libmbedtls14]Fixed
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
[libmbedtls-dev]Fixed
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
[libmbedtls-doc]Fixed
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · all · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
- 2.28.3-1 · all · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
[libmbedx509-1]Fixed
Source package: [mbedtls]
Details (2)
- 2.28.3-1 · amd64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12
- 2.28.3-1 · arm64 · bookworm
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · bookworm; dsa · mbedtls · debian · 12

[Debian 13 (Trixie)]

[libmbedcrypto16]Fixed
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
[libmbedtls21]Fixed
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
[libmbedtls-dev]Fixed
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
[libmbedtls-doc]Fixed
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · all · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · all · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
[libmbedx509-7]Fixed
Source package: [mbedtls]
Details (2)
- 3.6.5-0.1~deb13u1 · amd64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13
- 3.6.5-0.1~deb13u1 · arm64 · trixie
  Fixed · Fixed: 2.28.0-0.3
  dsa · mbedtls · debian · 13

Observed: Oct 23, 2026, 5:51:52 PM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database]