active_support/core_ext/hash/conversions.rb in Ruby on Rails before 2.3.15, 3.0.x before 3.0.19, 3.1.x before 3.1.10, and 3.2.x before 3.2.11 does not properly restrict casts of string values, which allows remote attackers to conduct object-injection attacks and execute arbitrary code, or cause a denial of service (memory and CPU consumption) involving nested XML entity references, by leveraging Action Pack support for (1) YAML type conversion or (2) Symbol type conversion.
CVE-2013-0156
HIGHCVSS v2 · 7.57.5—Trending — 3 sources updated this weekWeaponized
EchelonGraph scoreLOW confidence
This CVE was only ever scored under CVSS v2.0. NVD CVSS v2.0 base 7.5 — v2 rates that HIGH (v2 bands: LOW 0.0–3.9 / MEDIUM 4.0–6.9 / HIGH 7.0–10.0; v2 has no CRITICAL band). Vector AV:N/AC:L/Au:N/C:P/I:P/A:P. CVSS v2 is an older, coarser metric than v3.1/v4.0 (no Scope, no User Interaction, no Attack Requirements), so it is not directly comparable to a v3 or v4 score. NVD has never re-scored this record under v3. EPSS predicts 99.4% exploitation probability in the next 30 days, which is reflected in EG Risk but does not lift the v2 base. Confidence: LOW.
Sources: epss, nvd_v2
7.5EG
EchelonGraph verdictPatch this weekExploitation is likely or a public exploit exists.
- High exploitation likelihood — EPSS 99%
- Public exploit code is available (Metasploit, Exploit-DB (verified), epss top5pct, epss high, public exploit)
CISA-KEV: Not listedEPSS PROB: 99%CVSS v2: 7.5Exploit: Metasploit · Exploit-DB (verified) · epss top5pct · epss high · public exploitExposed services: Not assessed
A fix is available — apply it.
- CVSS v2.0 (legacy)
- 7.5HIGHNVD never assigned a CVSS v3 rating to this CVE
- EG Score
- 7.5HIGHlow confidence
- EG Risk
- 78EG Risk 78/100CISA SSVC
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity75% × 45%Exploitation99% × 40%Automatability30% × 15%CISA SSVC: Track at low, Track or Track* at medium and Track* or Attend at high mission impact.Action: A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high. - EPSS PROB
- 99%
- EPSS %ILE
- 99th
- KEV
- Not listed
CISA SSVCTrack at low, Track or Track* at medium and Track* or Attend at high mission impact.
A fix is available. Apply it within your standard update timelines at low or medium mission impact and sooner than that at high.
Exploitation public PoC (EG-KEV: weaponized) · Automatable unknown (not published for this CVE) · Technical impact unknown (not published for this CVE). Mission impact is CISA's Mission & Well-being decision point, and only you can judge it: high means the affected system is essential to your organisation's mission, or its compromise could cause irreversible harm to people. CISA's decision table
Published
January 13, 2013
Last Modified
April 29, 2026
References (28)
- secalert@redhathttp://ics-cert.us-cert.gov/advisories/ICSA-13-036-01A
- secalert@redhathttp://lists.apple.com/archives/security-announce/2013/Mar/msg00002.html
- secalert@redhathttp://rhn.redhat.com/errata/RHSA-2013-0153.html
- secalert@redhathttp://rhn.redhat.com/errata/RHSA-2013-0154.html
- secalert@redhathttp://rhn.redhat.com/errata/RHSA-2013-0155.html
- secalert@redhathttp://weblog.rubyonrails.org/2013/1/28/Rails-3-0-20-and-2-3-16-have-been-released/
- secalert@redhathttp://www.debian.org/security/2013/dsa-2604
- secalert@redhathttp://www.fujitsu.com/global/support/software/security/products-f/sw-sv-rcve-ror201301e.html
- secalert@redhathttp://www.insinuator.net/2013/01/rails-yaml/
- secalert@redhathttp://www.kb.cert.org/vuls/id/380039
- secalert@redhathttp://www.kb.cert.org/vuls/id/628463
- secalert@redhathttps://community.rapid7.com/community/metasploit/blog/2013/01/09/serialization-mischief-in-ruby-land-cve-2013-0156
- secalert@redhathttps://groups.google.com/group/rubyonrails-security/msg/c1432d0f8c70e89d?dmode=source&output=gplain
- secalert@redhathttps://puppet.com/security/cve/cve-2013-0156
- af854a3a-2127-422b-91ae-364da2661108http://ics-cert.us-cert.gov/advisories/ICSA-13-036-01A
Vendor Advisories for CVE-2013-0156(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Patch Availability(2)
| Vendor / Ecosystem | Fix (by version range) / Patch | Released | Source |
|---|---|---|---|
| redhat | rubygem-activesupport-1:3.0.10-5.el6cf | 2013-01-10 | redhat |
| redhat | rubygem-activesupport-1:3.0.13-2.el6op | 2013-01-10 | redhat |
Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.
Affected Packages
(6 across 6 ecosystems)
Debian:11(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rails | — |
| — |
Debian:12(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rails | — |
| — |
Debian:13(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rails | — |
| — |
Debian:14(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rails | — |
| — |
Debian:6.0(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| rails | 2.3.5-1.2 ... 2.3.5-1.2+squeeze4 (6 versions) |
| — |
RubyGems(1)
| Package | Vulnerable range | Fix by version range | Dependents |
|---|---|---|---|
| actionpack | 3.2.0 ... 3.2.9.rc3 (21 versions) |
| — |
Additional Vendor Advisories
(2)
Vendors that published advisories for this CVE beyond the curated set above. Broader coverage but minimal per-row detail — click through for the original advisory.
Data Freshness Timeline
(refreshed 3× in last 7d / 6× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-10-01 05:10 UTCOSV refresh
- 2026-09-30 14:58 UTCEPSS rescore
- 2026-09-29 08:34 UTCEG score recompute
- 2026-09-12 07:10 UTCOSV refresh
- 2026-09-11 09:30 UTCEPSS rescore
- 2026-09-06 13:42 UTCEPSS rescore
- 2026-09-05 15:22 UTCEPSS rescore
- 2026-09-01 13:47 UTCEPSS rescore
- 2026-08-24 12:30 UTCOSV refresh
- 2026-08-21 23:44 UTCEPSS rescore
- 2026-08-12 13:45 UTCEPSS rescore
- 2026-08-08 08:19 UTCOSV refresh
- 2026-08-02 02:22 UTCEPSS rescore
- 2026-07-26 13:47 UTCEG score recompute▲ 7.50
- 2026-07-23 01:13 UTCVendor advisory
- 2026-07-23 01:11 UTCVendor advisory
- 2026-07-23 01:09 UTCEG score recompute▼ 9.00
- 2026-07-23 00:12 UTCEG score recompute
- 2026-07-22 21:50 UTCEG score recompute
- 2026-07-22 14:50 UTCOSV refresh
- 2026-07-11 08:23 UTCEPSS rescore
- 2026-07-05 10:29 UTCOSV refresh
- 2026-07-01 15:02 UTCEPSS rescore
- 2026-06-16 21:35 UTCOSV refresh
- 2026-06-15 17:44 UTCEPSS rescore
Show 17 moreShow fewer
- 2026-06-12 23:08 UTCEPSS rescore
- 2026-06-10 13:18 UTCEPSS rescore
- 2026-06-08 14:14 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-06 13:45 UTCEPSS rescore
- 2026-06-05 22:44 UTCEPSS rescore
- 2026-06-05 22:44 UTCEPSS rescore
- 2026-05-29 13:41 UTCEPSS rescore
- 2026-05-29 13:41 UTCEPSS rescore
- 2026-05-29 01:21 UTCEG score recompute
- 2026-05-29 01:21 UTCVendor advisory
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-28 13:42 UTCEPSS rescore
- 2026-05-20 20:03 UTCOSV refresh
- 2026-05-18 21:29 UTCEPSS rescore
- 2026-05-18 21:29 UTCEPSS rescore
Publicly available exploits
(6 references)Working exploit code is in the public domain (3 Metasploit modules) (1 GitHub PoC) (2 Exploit-DB entries). Defenders should treat patch urgency accordingly — public PoCs typically lead to mass-exploitation within 24-72 hours.
- Exploit-DBEDB-27527✓ verifiedFirst seen Aug 12, 2013
Ruby on Rails - Known Secret Session Cookie Remote Code Execution (Metasploit)
Open source ↗ - Metasploitexploit/multi/http/rails_secret_deserialization✓ verifiedFirst seen Apr 11, 2013
Ruby on Rails Known Secret Session Cookie Remote Code Execution
Open source ↗ - Exploit-DBEDB-24019✓ verifiedFirst seen Jan 10, 2013
Ruby on Rails - XML Processor YAML Deserialization Code Execution (Metasploit)
Open source ↗ - Metasploitexploit/multi/http/rails_xml_yaml_code_exec✓ verifiedFirst seen Jan 7, 2013
Ruby on Rails XML Processor YAML Deserialization Code Execution
Open source ↗ - Metasploitauxiliary/scanner/http/rails_xml_yaml_scanner✓ verifiedFirst seen Jan 1, 2013
Ruby on Rails XML Processor YAML Deserialization Scanner
Open source ↗ - GitHub PoCbsodmike/rails-exploit-cve-2013-0156First seen Jan 12, 2013
Bootstrapped Rails 3.2.10 to test the remote code exploit CVE-2013-0156
Open source ↗
Related CVEs(same product + same vendor)
Same product
10 shownDebian:6.0:rails
Same vendor
10 shownredhat:RHSA-2013:0154
Frequently asked(4)
What is CVE-2013-0156?
CVE-2013-0156 is a high vulnerability published on January 13, 2013. activesupport/coreext/hash/conversions.rb in Ruby on Rails before 2.3.15, 3.0.x before 3.0.19, 3.1.x before 3.1.10, and 3.2.x before 3.2.11 does not properly restrict casts of string values, which allows remote attackers to conduct object-injection attacks and execute arbitrary code, or cause a…
When was CVE-2013-0156 disclosed?
CVE-2013-0156 was first published on January 13, 2013, with the most recent update on April 29, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2013-0156 actively exploited?
CVE-2013-0156 is not currently on CISA's Known Exploited Vulnerabilities catalog. EchelonGraph's EG-KEV model classifies it as weaponized: a functional public exploit exists. FIRST EPSS estimates a 99% probability of exploitation in the next 30 days (99th percentile of EPSS-scored CVEs).
How do I remediate CVE-2013-0156?
A fix for CVE-2013-0156 is available: update to the fixed version the vendor names in its advisory. The vendor advisories EchelonGraph has for CVE-2013-0156 are linked in the Vendor Advisories panel on this page.
Dependency Blast Radius
See which npm, PyPI, Go, and Maven packages are affected by CVE-2013-0156
Is Your Infrastructure Affected by CVE-2013-0156?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.