UBUNTU-CVE-2020-36477

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Source
https://ubuntu.com/security/CVE-2020-36477
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-36477.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2020-36477
Upstream
Published
2021-08-23T02:15:00Z
Modified
2025-10-13T04:46:42Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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 mbedtlsx509crt_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).

References

Affected packages

Ubuntu:Pro:16.04:LTS / mbedtls

Package

Name
mbedtls
Purl
pkg:deb/ubuntu/mbedtls@2.2.1-2ubuntu0.3?arch=source&distro=esm-apps/xenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.1.2-1
2.2.0-1
2.2.1-1
2.2.1-2
2.2.1-2ubuntu0.1
2.2.1-2ubuntu0.2
2.2.1-2ubuntu0.3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.2.1-2ubuntu0.3",
            "binary_name": "libmbedcrypto0"
        },
        {
            "binary_version": "2.2.1-2ubuntu0.3",
            "binary_name": "libmbedtls-dev"
        },
        {
            "binary_version": "2.2.1-2ubuntu0.3",
            "binary_name": "libmbedtls10"
        },
        {
            "binary_version": "2.2.1-2ubuntu0.3",
            "binary_name": "libmbedx509-0"
        }
    ]
}

Ubuntu:Pro:18.04:LTS / mbedtls

Package

Name
mbedtls
Purl
pkg:deb/ubuntu/mbedtls@2.8.0-1?arch=source&distro=esm-apps/bionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.5.1-1ubuntu1
2.6.0-1
2.7.0-2
2.8.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.8.0-1",
            "binary_name": "libmbedcrypto1"
        },
        {
            "binary_version": "2.8.0-1",
            "binary_name": "libmbedtls-dev"
        },
        {
            "binary_version": "2.8.0-1",
            "binary_name": "libmbedtls10"
        },
        {
            "binary_version": "2.8.0-1",
            "binary_name": "libmbedx509-0"
        }
    ]
}

Ubuntu:Pro:20.04:LTS / mbedtls

Package

Name
mbedtls
Purl
pkg:deb/ubuntu/mbedtls@2.16.4-1ubuntu2?arch=source&distro=esm-apps/focal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.16.2-1
2.16.3-1
2.16.4-1ubuntu2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_version": "2.16.4-1ubuntu2",
            "binary_name": "libmbedcrypto3"
        },
        {
            "binary_version": "2.16.4-1ubuntu2",
            "binary_name": "libmbedtls-dev"
        },
        {
            "binary_version": "2.16.4-1ubuntu2",
            "binary_name": "libmbedtls12"
        },
        {
            "binary_version": "2.16.4-1ubuntu2",
            "binary_name": "libmbedx509-0"
        }
    ]
}