CVE-2013-1821 — jruby
CVE-2013-1821 is a Improper Input Validation vulnerability in org.jruby:jruby. A fix is available for org.jruby:jruby — see the affected versions and patch details below.
Ruby vulnerable to denial of service
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Real-World Exposure
org.jruby:jrubyReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.
Description
When reading text nodes from an XML document, the REXML parser can be coerced in to allocating extremely large string objects which can consume all of the memory on a machine, causing a denial of service.
Jruby resolves this bug in version 1.7.3 as noted in https://www.jruby.org/2013/02/21/jruby-1-7-3.html
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.jruby:jruby | all versions | 1.7.3org.jruby:jruby:1.7.3 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.jruby:jruby, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update org.jruby:jruby to 1.7.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-1821 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2013-1821 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2013-1821. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
| Product | Fixed in | Advisory |
|---|---|---|
| Fuse ESB Enterprise 7.1.0 | see advisory | RHSA-2013:1028 |
| Red Hat Enterprise Linux 5 | ruby-0:1.8.5-29.el5_9 | RHSA-2013:0611 |
| Red Hat Enterprise Linux 6 | ruby-0:1.8.7.352-10.el6_4 | RHSA-2013:0612 |
| Red Hat JBoss Fuse 6.0 | see advisory | RHSA-2013:1185 |
| Red Hat JBoss SOA Platform 5.3 | see advisory | RHSA-2013:1147 |
| Red Hat Hardened Images | ruby3-3-main-3.3.10-23.1.hum1 | RHSA-2026:7305 |
| Red Hat Hardened Images | ruby3-4-main-3.4.8-31.1.hum1 | RHSA-2026:7307 |
| Red Hat Hardened Images | ruby4-0-main-4.0.0-33.3.hum1 | RHSA-2026:8838 |
Frequently Asked Questions
Is CVE-2013-1821 in your dependencies?
O3 Security finds CVE-2013-1821 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.