#VU31993 Use of a broken or risky cryptographic algorithm in GnuPG - CVE-2019-14855

Vulnerability identifier: #VU31993

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-14855

CWE-ID: CWE-327

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
GnuPG
Client/Desktop applications / Encryption software

Vendor: GNU

Description

The vulnerability allows a remote non-authenticated attacker to gain access to sensitive information.

A flaw was found in the way certificate signatures could be forged using collisions found in the SHA-1 algorithm. An attacker could use this weakness to create forged certificate signatures. This issue affects GnuPG versions before 2.2.18.

Mitigation
Install update from vendor's website.

Vulnerable software versions

GnuPG: 2.2.1 - 2.2.17

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2019-14855
https://dev.gnupg.org/T4755
https://lists.gnupg.org/pipermail/gnupg-announce/2019q4/000442.html
https://rwc.iacr.org/2020/slides/Leurent.pdf

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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.