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Fencer Vulns
critical 10.0

CVE-2009-4124 json

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…

published 2009-12-11 16 y ago modified 2026-06-16 4 mo ago also EUVD-2009-4094

cvss
10.0
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
3.9%
EPSS 3.9% chance of exploitation in 30 days, percentile 90%
public exploits
0
none known

Summary

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.

Patch / fix

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2009-4124 updated cvss 6.8

ruby: Heap-based buffer overflow in the rb_str_justify() function

  • Red Hat Enterprise Linux 5 ruby Red Hat Enterprise Linux 6 ruby, ruby-ri, ruby-irb, ruby-libs, ruby-rdoc, ruby-tcltk
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

3.88% chance of exploitation in the next 30 days, higher than 90% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 2.0 10.0 AV:N/AC:L/Au:N/C:C/I:C/A:C

Classification

Weakness
  • CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.