#VU29223 Improper Verification of Cryptographic Signature in jsrsasign - CVE-2020-14966

Vulnerability identifier: #VU29223

Vulnerability risk: Medium

CVSSv4.0: 2.7 [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]

CVE-ID: CVE-2020-14966

CWE-ID: CWE-347

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
jsrsasign
Web applications / Modules and components for CMS

Vendor: Restaumatic

Description

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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

jsrsasign: 0.0.1 - 8.0.17

---

External links
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

---

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.