CVE-2009-4124

Heap-based buffer overflow in the rb_str_justify function in string.c in Ruby 1.9.1 before 1.9.1-p376 allows context-dependent attackers to execute arbitrary code via unspecified vectors involving (1) String#ljust, (2) String#center, or (3) String#rjust. NOTE: some of these details are obtained from third party information.

Published: 2009-12-11 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2009-4124 is rated High Risk (73/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 3.88%). EPSS rose +1.94% over the last day, indicating growing attacker interest. High exploitation likelihood—assess exposure and prioritize remediation.

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

Exploit prediction scoring system (EPSS) score for CVE-2009-4124

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 1.93% 3.88% +1.94%
2 2026-02-27 2.05% 1.93% -0.12%
3 2025-05-04 — 2.05% —

Full EPSS history (10 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2009-4124

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
10.0 2.0 HIGH
AV:N/AC:L/Au:N/C:C/I:C/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:C)
Complete confidentiality impact.
Integrity impact (I:C)
Complete integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 10.0 [email protected]

Weakness enumeration for CVE-2009-4124

OS Trackers for CVE-2009-4124

vendor priority summary link
redhat medium — https://access.redhat.com/security/cve/CVE-2009-4124
ubuntu medium CVE-2009-4124 medium priority: Ubuntu including 3 source packages (ruby1.8, ruby1.9, ruby1.9.1), 30 status rows across 10 suites (dapper, hardy, intrepid, jaunty, karmic, lucid, maverick, natty, oneiric, upstream): not-affected 13, DNE 7, released 5, ignored 3, needed 1, needs-triage 1. https://ubuntu.com/security/CVE-2009-4124

Affected software / configurations for CVE-2009-4124

Vendor Product Version Raw CPE
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-p0:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-p129:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-p243:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-preview_1:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-preview_2:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-rc1:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:-rc2:*:*:*:*:*:*

References for CVE-2009-4124

cvelogic Threat Intelligence