How severe is CVE-2013-1856?

No CVSS score has been assigned to CVE-2013-1856 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2013-1856?

CVE-2013-1856 affects the following packages: activesupport (RubyGems), activesupport (RubyGems). Ecosystems affected: RubyGems.

How do I fix CVE-2013-1856?

Update activesupport to 3.1.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-1856 is resolved across your whole dependency graph.

How do I detect CVE-2013-1856 in my RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activesupport, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2013-1856 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2013-1856 actively exploited in the wild?

No public exploit code has been indexed for CVE-2013-1856 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2013-1856?

CVE-2013-1856 has an EPSS (Exploit Prediction Scoring System) score of 2.1%, placing it in the 81th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2013-1856?

CVE-2013-1856 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2013-1856 published, and has it been updated?

CVE-2013-1856 was published on October 24, 2017 and was last updated on December 5, 2024. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

💎 RubyGems

Not in CISA KEV

CVE-2013-1856 — activesupport

CVE-2013-1856 is a Improper Input Validation vulnerability in activesupport. A fix is available for activesupport — see the affected versions and patch details below.

activesupport Improper Input Validation vulnerability

Published

Oct 24, 2017

Updated

Dec 5, 2024

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 1, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

2.1%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs81th percentile — riskier than 81% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

💎activesupport💎activesupport

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.

Description

The ActiveSupport::XmlMini_JDOM backend in lib/active_support/xml_mini/jdom.rb in the Active Support component in Ruby on Rails 3.0.x and 3.1.x before 3.1.12 and 3.2.x before 3.2.13, when JRuby is used, does not properly restrict the capabilities of the XML parser, which allows remote attackers to read arbitrary files or cause a denial of service (resource consumption) via vectors involving (1) an external DTD or (2) an external entity declaration in conjunction with an entity reference.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
💎RubyGems	`activesupport`	≥ 3.0.0&&< 3.1.12	3.1.12`bundle update activesupport --conservative`
💎RubyGems	`activesupport`	≥ 3.2.0&&< 3.2.13	3.2.13`bundle update activesupport --conservative`

Affected Products

2 products · 47 configurations

Application

railsrubyonrails

24 versions

3.1.03.1.13.1.23.1.33.1.43.1.53.1.63.1.73.1.83.1.93.1.103.2.0

Application

ruby on railsrubyonrails

1 version

3.1.11

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activesupport, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update activesupport to 3.1.12 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-1856 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Frequently Asked Questions

The `ActiveSupport::XmlMini_JDOM` backend in `lib/active_support/xml_mini/jdom.rb` in the Active Support component in Ruby on Rails 3.0.x and 3.1.x before 3.1.12 and 3.2.x before 3.2.13, when JRuby is used, does not properly restrict the capabilities of the XML parser, which allows remote attackers to read arbitrary files or cause a denial of service (resource consumption) via vectors involving (1) an external DTD or (2) an external entity declaration in conjunction with an entity reference.

O3 Security · Impact-Aware SCA

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