CVE-2016-7798
ruby: IV Reuse in GCM Mode
Severity
ModerateRed Hat Product Security
CVSS 3.0
Review impact separately from score.
Published · September 19, 2016
Updated · May 13, 2026
Description
The openssl gem for Ruby uses the same initialization vector (IV) in GCM Mode (aes-*-gcm) when the IV is set before the key, which makes it easier for context-dependent attackers to bypass the encryption protection mechanism.
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
A possible workaround to this flaw is, when using aes-256-gcm mode, always set the key first and then the iv. For example when setting random keys and iv use the following code segment:
key = cipher.random_key iv = cipher.random_iv
CVSS / CWE
CVSS 3.0 · 3.7CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:N
CVSS 2.0 · 4.3AV:N/AC:M/Au:N/C:P/I:N/A:N
CWE not specified