SB2020062405 - Multiple vulnerabilities in jsrsasign JavaScript library

Description

This security bulletin contains information about 2 vulnerabilities.

1) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2020-14966)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the affected software allows a malleability in ECDSA signatures by not checking overflows in the length of a sequence and "0" characters appended or prepended to an integer. A remote attacker can cause a security-relevant impact if an application relied on a single canonical signature.

2) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2020-14967)

CWE-ID: CWE-347 - Improper Verification of Cryptographic Signature

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to compromise the target system.

The vulnerability exists due to the RSA PKCS1 v1.5 decryption implementation does not detect ciphertext modification by prepending "\0" bytes to ciphertexts. A remote attacker can prepend these bytes with the goal of triggering memory corruption issues.

Remediation

Install update from vendor's website.

References

• https://github.com/kjur/jsrsasign/issues/437
• https://github.com/kjur/jsrsasign/releases/tag/8.0.17
• https://github.com/kjur/jsrsasign/releases/tag/8.0.18
• https://kjur.github.io/jsrsasign/
• https://www.npmjs.com/package/jsrsasign
• https://github.com/kjur/jsrsasign/issues/439