#VU28771 Improper Verification of Cryptographic Signature in p5-Crypt-Perl - CVE-2020-13895

Vulnerability identifier: #VU28771

Vulnerability risk: Medium

CVSSv4.0: 4.8 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2020-13895

CWE-ID: CWE-347

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
p5-Crypt-Perl
Universal components / Libraries / Software for developers

Vendor: Felipe Gasper

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: 0.11 - 0.033

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External links
https://github.com/FGasper/p5-Crypt-Perl/commit/f960ce75502acf7404187231a706672f8369acb2
https://github.com/FGasper/p5-Crypt-Perl/issues/14

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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.