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Fencer Intel
medium 5.1

CVE-2013-0263 json

Rack arbitrary code execution via timing attack

published 2013-02-08 13 y ago modified 2026-06-16 4 mo ago also GHSA-xc85-32mf-xpv8 , EUVD-2022-5763

cvss
5.1
version 2.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.4%
EPSS 5.4% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

Rack::Session::Cookie in Rack 1.5.x before 1.5.2, 1.4.x before 1.4.5, 1.3.x before 1.3.10, 1.2.x before 1.2.8, and 1.1.x before 1.1.6 allows remote attackers to guess the session cookie, gain privileges, and execute arbitrary code via a timing attack involving an HMAC comparison function that does not run in constant time.

Patch / fix

  • rubygems rack 1.1.6, 1.2.8, 1.3.10, 1.4.5, 1.5.2
  • ruby-rack Debian 14, Debian 13, Debian 12 1.4.1-2.1

debian advisories DEBIAN-CVE-2013-0263

  • ruby-rack Ubuntu 14.04 LTS 1.5.2-1

ubuntu advisories UBUNTU-CVE-2013-0263

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • jenkins openshift 1 1.502-1.el6op
  • rubygem-rack openshift 1 1:1.3.0-4.el6op
  • ruby193-rubygem-rack openshift 1 1:1.4.1-4.el6
  • openshift-origin-cartridge-jenkins-1.4 openshift 1 1.0.3-1.el6op

red hat advisories RHSA-2013:0638

  • rubygem-rack openSUSE Tumbleweed 3.1.18-1.3
  • rubygem-rack-2.2 openSUSE Tumbleweed 2.2.22-1.1
  • rubygem-rack openSUSE Tumbleweed 3.1.12-1.1
  • rubygem-rack-2.2 openSUSE Tumbleweed 2.2.11-1.1
  • rubyem-rack openSUSE Tumbleweed 1.4.7-1.8
  • rubygem-rack openSUSE Tumbleweed 2.2.3.1-1.1
  • rubygem-rack-2.2 openSUSE Tumbleweed 2.2.4-1.1
  • ruby3.2-rubygem-rack-2.2 openSUSE Tumbleweed 2.2.7-1.1

opensuse advisories openSUSE-SU-2026:10358-1openSUSE-SU-2026:10286-1openSUSE-SU-2025:14875-1openSUSE-SU-2025:14811-1openSUSE-SU-2024:10115-1openSUSE-SU-2024:12119-1

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-2013-0263 updated cvss 5.0

rubygem-rack: Timing attack in cookie sessions

  • Red Hat Enterprise MRG 2 rubygem-rack
    affected: no fix available
  • Red Hat OpenShift Enterprise Infrastructure rubygem-rack 1.3.0-4.el6op, ruby193-rubygem-rack 1.4.1-4.el6 Red Hat OpenShift Enterprise Node jenkins 1.502-1.el6op, rubygem-rack 1.3.0-4.el6op, ruby193-rubygem-rack 1.4.1-4.el6, openshift-origin-cartridge-jenkins-1.4 1.0.3-1.el6op
    fixed: vendor fix RHSA-2013:0638
  • Red Hat Subscription Asset Manager for RHEL 6 Server candlepin 0.7.24-1.el6_3, katello 1.2.1.1-1h.el6_4, rubygem-rdoc 3.8-6.el6cf, rubygem-json 1.7.3-2.el6_3, rubygem-rack 1.3.0-4.el6cf, thumbslug 0.0.28.1-1.el6_4, +14 more
    fixed: vendor fix RHSA-2013:0686

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

5.38% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 2.0 5.1 AV:N/AC:H/Au:N/C:P/I:P/A:P

Affected packages

ecosystem package affected fixed in
rubygems rack
>=1.5.0, <1.5.2
>=1.4.0, <1.4.5
>=1.3.0, <1.3.10
>=1.2.0, <1.2.8
>=1.1.0, <1.1.6
1.5.2
1.4.5
1.3.10
1.2.8
1.1.6

References

Sources

Fencer Intel 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.