Side-channel attack in Libgcrypt - CVE-2017-9526

Vulnerability identifier: #VU7299

CSH Severity: Low

CVSS v4: 6.3 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2017-9526

CWE-ID: CWE-310

Exploitation vector: Remote access

Exploit availability: No public exploit available

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

The vulnerability exists in libgcrypt's EdDSA implementation. An attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key.

Libgcrypt
Debian Linux
Ubuntu
libgcrypt (Alpine package)

Update to version 1.7.7.

libgcrypt (Alpine package) - addressed in versions 1.7.7-r0, 1.7.8-r0

• https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=f9494b3f258e01b6af8bd3941ce436bc...
• https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git;a=commit;h=5a22de904a0a366ae79f03ff1e13a123...
• https://bugzilla.suse.com/show_bug.cgi?id=1042326

• Side-channel attack in Libcrypt
• Ubuntu update for Libgcrypt
• Debian update for libgcrypt20
• Side-channel attack in libgcrypt (Alpine package)