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💎 RubyGems
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CVE-2013-4389 actionmailer

CVE-2013-4389 is a CWE-134 vulnerability in actionmailer. 1 public exploit reference exists, so weaponization risk is real. A fix is available for actionmailer — see the affected versions and patch details below.

actionmailer email address processing causes Denial of service

Published
Oct 24, 2017
Updated
Dec 6, 2024
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Sep 21, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
3.1%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs87th percentile — riskier than 87% of all scored CVEsHighest risk

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

1 pkg affected
💎actionmailer

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

Multiple format string vulnerabilities in log_subscriber.rb files in the log subscriber component in Action Mailer in Ruby on Rails 3.x before 3.2.15 allow remote attackers to cause a denial of service via a crafted e-mail address that is improperly handled during construction of a log message.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
💎RubyGemsactionmailer3.0.0&&< 3.2.153.2.15bundle update actionmailer --conservative
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

Detection & mitigation playbook

Open-source dependency
  1. Detect

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

  2. Fix

    Update actionmailer to 3.2.15 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2013-4389 is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2013-4389 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2013-4389. 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.

Red HatLow

Red Hat Product Security has rated this issue as having Low security impact. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Issue Severity Classification: https://access.redhat.com/security/updates/classification/. This issue did not affect the versions…

ProductFixed inAdvisory
CloudForms Management Engine 5.4cfme-0:5.4.0.5-1.el6cfRHBA-2015:1100

Frequently Asked Questions

Multiple format string vulnerabilities in log_subscriber.rb files in the log subscriber component in Action Mailer in Ruby on Rails 3.x before 3.2.15 allow remote attackers to cause a denial of service via a crafted e-mail address that is improperly handled during construction of a log message.
O3 Security · Impact-Aware SCA

Is CVE-2013-4389 in your dependencies?

O3 Security finds CVE-2013-4389 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2013-4389: actionmailer DoS | O3 Security