#VU7276 Side-channel attack in Libgcrypt - CVE-2017-7526

Vulnerability identifier: #VU7276

Vulnerability risk: Low

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2017-7526

CWE-ID: CWE-310

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Libgcrypt
Client/Desktop applications / Encryption software

Vendor: GNU

Description
The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists in libgcrypt's RSA-1024 implementation using left-to-right method for computing the sliding-window expansion. A remote attacker can perform side-channel attack and gain access to potentially sensitive information. 

Mitigation
Update libgcrypt to version 1.7.8.

Vulnerable software versions

Libgcrypt: 1.7.0 - 1.7.7

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-7526
https://lists.gnupg.org/pipermail/gnupg-announce/2017q2/000408.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.