SB2021040633 - MitM attack in phpseclib
Published: April 6, 2021 Updated: May 21, 2026
Security Bulletin ID
SB2021040633
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities
1
Exploitation vector
Remote access
Highest impact
Data manipulation
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Improper verification of cryptographic signature (CVE-ID: CVE-2021-30130)
CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature
CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N]
The vulnerability allows a remote attacker to perform MitM attack.
The vulnerability exists due to improper verification of RSA PKCS#1 v1.5 signature. A remote attacker can perform MitM attack.
Remediation
Install update from vendor's website.
References
- https://github.com/phpseclib/phpseclib/releases/tag/2.0.31
- https://github.com/phpseclib/phpseclib/pull/1635
- https://github.com/phpseclib/phpseclib/releases/tag/3.0.7
- https://lists.debian.org/debian-lts-announce/2022/11/msg00024.html
- https://lists.debian.org/debian-lts-announce/2022/11/msg00025.html
- https://github.com/phpseclib/phpseclib/security/advisories/GHSA-8p5q-f4jq-7rr3