CVE-2017-7526
libgcrypt: Use of left-to-right sliding window method allows full RSA key recovery
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · June 29, 2017
Updated · June 30, 2026
Description
libgcrypt before version 1.7.8 is vulnerable to a cache side-channel attack resulting into a complete break of RSA-1024 while using the left-to-right method for computing the sliding-window expansion. The same attack is believed to work on RSA-2048 with moderately more computation. This side-channel requires that attacker can run arbitrary software on the hardware where the private RSA key is used.
Statement
This side-channel attack requires that the attacker can run arbitrary software on the hardware where the private RSA key is used. Allowing execute access to a box with private keys should be considered as an unsafe security practice, anyway. Thus in practice there are easier ways to access the private keys than to mount this side-channel attack. However, on boxes with virtual machines this attack may be used by one VM to steal private keys from another VM.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.0 · 6.1CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:N/A:N
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor