Security restrictions bypass in p5-Crypt-Perl

1) Improper Verification of Cryptographic Signature

EUVDB-ID: #VU28771

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2020-13895

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

Exploit availability: No

Description

The vulnerability allows a remote attacker to bypass implemented security restrictions.

The vulnerability exists due to improper ECDSA signature verification for the secp256r1 (prime256v1) curve, when r and s are small and when s = 1. A remote attacker can bypass signature verification process for Crypt::Perl::ECDSA and trick the victim into installing malicious code.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

p5-Crypt-Perl: 0.021 - 0.31

External links

http://github.com/FGasper/p5-Crypt-Perl/commit/f960ce75502acf7404187231a706672f8369acb2
http://github.com/FGasper/p5-Crypt-Perl/issues/14

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.