#VU33822 Input validation error in GnuPG - CVE-2015-0837

Vulnerability identifier: #VU33822

Vulnerability risk: Medium

CVSSv4.0: 4.6 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2015-0837

CWE-ID: CWE-20

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.

The mpi_powm function in Libgcrypt before 1.6.3 and GnuPG before 1.4.19 allows attackers to obtain sensitive information by leveraging timing differences when accessing a pre-computed table during modular exponentiation, related to a "Last-Level Cache Side-Channel Attack."

Mitigation
Install update from vendor's website.

Vulnerable software versions

GnuPG: 1.4.0 - 1.4.18

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External links
https://www.debian.org/security/2015/dsa-3184
https://www.debian.org/security/2015/dsa-3185
https://ieeexplore.ieee.org/document/7163050
https://lists.gnupg.org/pipermail/gnupg-announce/2015q1/000363.html
https://lists.gnupg.org/pipermail/gnupg-announce/2015q1/000364.html

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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.