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Ubuntu Security Notice USN-7404-1
April 02, 2025

phpseclib vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in phpseclib.

Software Description:
- php-phpseclib: implementations of an arbitrary-precision integer arithmetic
- php-phpseclib3: implementations of an arbitrary-precision integer arithmetic
- phpseclib: implementations of an arbitrary-precision integer arithmetic

Details:

It was discovered that phpseclib did not correctly handle RSA PKCS#1
v1.5 signature verification. An attacker could possibly use this issue to
bypass authentication. This issue only affected Ubuntu 20.04 LTS.
(CVE-2021-30130)

It was discovered that phpseclib did not correctly handle certain
characters in certain TLS fields, which could lead to name confusion.
An attacker could possibly use this issue to bypass authentication.
(CVE-2023-52892)

It was discovered that phpseclib incorrectly limited the size of prime
numbers generated by isPrime. An attacker could possibly use this issue
to cause a denial of service. (CVE-2024-27354)

It was discovered that phpseclib did not correctly handle processing the
ASN.1 object identifier of a certificate. An attacker could possibly use
this issue to cause a denial of service. This issue only affected
Ubuntu 20.04 LTS and Ubuntu 22.04 LTS. (CVE-2024-27355)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 22.04 LTS
  php-phpseclib                   2.0.36-1ubuntu0.1~esm2
                                  Available with Ubuntu Pro
  php-phpseclib3                  3.0.13-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro
  php-seclib                      1.0.20-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

Ubuntu 20.04 LTS
  php-phpseclib                   2.0.23-2ubuntu0.1~esm2
                                  Available with Ubuntu Pro
  php-seclib                      1.0.18-2ubuntu0.1~esm1
                                  Available with Ubuntu Pro

Ubuntu 18.04 LTS
  php-phpseclib                   2.0.9-1ubuntu0.1~esm2
                                  Available with Ubuntu Pro
  php-seclib                      1.0.9-1ubuntu0.1~esm1
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  php-phpseclib                   2.0.1-1ubuntu0.1~esm2
                                  Available with Ubuntu Pro
  php-seclib                      1.0.1-3ubuntu0.1+esm1
                                  Available with Ubuntu Pro

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-7404-1
  CVE-2021-30130, CVE-2023-52892, CVE-2024-27354, CVE-2024-27355