HOMEVULNERABILITIESCVE-2011-4121
CRITICAL

CVE-2011-4121

CWE-326Published: November 26, 2019· Updated: Jun 16, 2026

9.8
CVSS v3.1

Official 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.

NVD Source

Technical Analysis

CVE-2011-4121 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected Vendors & Products

ruby-lang1 product(s)
ruby
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.

Official Patches & Advisories

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

All References (8)

→
http://www.openwall.com/lists/oss-security/2013/07/01/1Mailing List · Third Party Advisory
→
https://access.redhat.com/security/cve/cve-2011-4121Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4121Issue Tracking · Third Party Advisory
→
https://security-tracker.debian.org/tracker/CVE-2011-4121Third Party Advisory
→
http://www.openwall.com/lists/oss-security/2013/07/01/1Mailing List · Third Party Advisory
→
https://access.redhat.com/security/cve/cve-2011-4121Third Party Advisory
→
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2011-4121Issue Tracking · Third Party Advisory
→
https://security-tracker.debian.org/tracker/CVE-2011-4121Third Party Advisory

Quick Facts

CVE IDCVE-2011-4121
CVSS Score9.8 / 10
SeverityCRITICAL
WeaknessCWE-326
CISA KEVNo
Affected1 vendor(s)
PublishedNov 26, 2019

Related CVEs (CWE-326)

CVE-2014-9199
10.0
CVE-2026-44523
10.0
CVE-2020-6966
10.0
CVE-2018-7242
9.8
CVE-2017-8076
9.8
CVE-2014-9975
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2011-4121 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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