What’s Vulnerable › Vulnerabilities

CVE-2011-4121

• Severity: critical (CVSS 9.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 2.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2019-11-26 · updated 2026-06-16
• Weakness: CWE-326

Description

The OpenSSL extension of Ruby (Git trunk) versions after 2011-09-01 up to 2011-11-03 always generated an exponent value of '1' to be used for private RSA key generation. A remote attacker could use this flaw to bypass or corrupt integrity of services, depending on strong private RSA keys generation mechanism.

Affected products

• Ruby: from 1.8.7.334 before 1.9.3 — fixed in 1.9.3

How to fix

Upgrade to a fixed version: Ruby 1.9.3. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2013/07/01/1
• https://access.redhat.com/security/cve/cve-2011-4121
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4121
• https://security-tracker.debian.org/tracker/CVE-2011-4121
• http://www.openwall.com/lists/oss-security/2013/07/01/1
• https://access.redhat.com/security/cve/cve-2011-4121
• https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4121
• https://security-tracker.debian.org/tracker/CVE-2011-4121

Get alerted when CVE-2011-4121 or the next vulnerability affects your stack