CVE-2009-0642

Exp

ext/openssl/ossl_ocsp.c in Ruby 1.8 and 1.9 does not properly check the return value from the OCSP_basic_verify function, which might allow remote attackers to successfully present an invalid X.509 certificate, possibly involving a revoked certificate.

Published: 2009-02-20 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-0642 is rated High Exploit Risk (73.1/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.64%). 1 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.67% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2009-0642

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2009-0642

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.97% 2.64% +1.67%
2 2025-12-01 1.46% 0.97% -0.48%
3 2025-03-30 — 1.46% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-0642

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.8 2.0 MEDIUM
AV:N/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 8.6 6.4 [email protected]

Weakness enumeration for CVE-2009-0642

OS Trackers for CVE-2009-0642

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2009-0642
ubuntu low CVE-2009-0642 low priority: Ubuntu including 2 source packages (ruby1.8, ruby1.9), 22 status rows across 11 suites (dapper, gutsy, hardy, intrepid, jaunty, karmic, lucid, maverick, natty, oneiric, upstream): released 8, not-affected 7, ignored 4, DNE 3. https://ubuntu.com/security/CVE-2009-0642

Affected software / configurations for CVE-2009-0642

Vendor Product Version Raw CPE
ruby-lang ruby 1.8 cpe:2.3:a:ruby-lang:ruby:1.8:*:*:*:*:*:*:*
ruby-lang ruby 1.9 cpe:2.3:a:ruby-lang:ruby:1.9:*:*:*:*:*:*:*

References for CVE-2009-0642

cvelogic Threat Intelligence