CVE-2013-1821

lib/rexml/text.rb in the REXML parser in Ruby before 1.9.3-p392 allows remote attackers to cause a denial of service (memory consumption and crash) via crafted text nodes in an XML document, aka an XML Entity Expansion (XEE) attack.

Published: 2013-04-09 Last update: 2026-06-16 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2013-1821 is rated Moderate Risk (47.5/100): CVSS Medium severity, with high exploitation likelihood (EPSS 6.62%, 93th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2013-1821

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 25.73% 6.62% -19.11%
2 2026-05-31 26.22% 25.73% -0.49%
3 2026-05-18 26.22%

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2013-1821

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.0 2.0 MEDIUM
AV:N/AC:L/Au:N/C:N/I:N/A:P Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:P)
Partial availability impact.
10.0 2.9 [email protected]

Weakness enumeration for CVE-2013-1821

GitHub Security Advisory for CVE-2013-1821

GHSA-hgg7-cghq-xhf4 · Severity: medium · Ecosystem: maven — Ruby vulnerable to denial of service

OS Trackers for CVE-2013-1821

vendor priority summary link
gentoo normal CVE-2013-1821: 1 GLSA(s) (201412-27), 1 atom(s) (dev-lang/ruby); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2013-1821
redhat medium https://access.redhat.com/security/cve/CVE-2013-1821
ubuntu medium CVE-2013-1821 medium priority: Ubuntu including 2 source packages (ruby1.8, ruby1.9.1), 16 status rows across 8 suites (hardy, lucid, oneiric, precise, quantal, raring, saucy, upstream): released 10, ignored 3, not-affected 2, DNE 1. https://ubuntu.com/security/CVE-2013-1821

NVD evaluator notes for CVE-2013-1821

Impact: Per: http://www.ruby-lang.org/en/news/2013/02/22/rexml-dos-2013-02-22/ "Affected versions All ruby 1.9 versions prior to ruby 1.9.3 patchlevel 392 All ruby 2.0 versions prior to ruby 2.0.0 patchlevel 0 prior to trunk revision 39384"

Affected software / configurations for CVE-2013-1821

Vendor Product Version Raw CPE
ruby-lang ruby <= 1.9.3 cpe:2.3:a:ruby-lang:ruby:*:p385:*:*:*:*:*:*
ruby-lang ruby 1.9 cpe:2.3:a:ruby-lang:ruby:1.9:*:*:*:*:*:*:*
ruby-lang ruby 1.9.1 cpe:2.3:a:ruby-lang:ruby:1.9.1:*:*:*:*:*:*:*
ruby-lang ruby 1.9.2 cpe:2.3:a:ruby-lang:ruby:1.9.2:*:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:*:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p0:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p125:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p194:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p286:*:*:*:*:*:*
ruby-lang ruby 1.9.3 cpe:2.3:a:ruby-lang:ruby:1.9.3:p383:*:*:*:*:*:*
ruby-lang ruby 2.0 cpe:2.3:a:ruby-lang:ruby:2.0:*:*:*:*:*:*:*
ruby-lang ruby 2.0.0 cpe:2.3:a:ruby-lang:ruby:2.0.0:*:*:*:*:*:*:*
ruby-lang ruby 2.0.0 cpe:2.3:a:ruby-lang:ruby:2.0.0:rc1:*:*:*:*:*:*
ruby-lang ruby 2.0.0 cpe:2.3:a:ruby-lang:ruby:2.0.0:rc2:*:*:*:*:*:*

References for CVE-2013-1821

URL Tags
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=702525
http://lists.opensuse.org/opensuse-security-announce/2013-04/msg00001.html
http://lists.opensuse.org/opensuse-security-announce/2013-04/msg00015.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00034.html
http://lists.opensuse.org/opensuse-updates/2013-04/msg00036.html
http://rhn.redhat.com/errata/RHSA-2013-0611.html
http://rhn.redhat.com/errata/RHSA-2013-0612.html
http://rhn.redhat.com/errata/RHSA-2013-1028.html
http://rhn.redhat.com/errata/RHSA-2013-1147.html
http://secunia.com/advisories/52783 Vendor Advisory
http://secunia.com/advisories/52902 Vendor Advisory
http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=39384
http://www.debian.org/security/2013/dsa-2738
http://www.debian.org/security/2013/dsa-2809
http://www.mandriva.com/security/advisories?name=MDVSA-2013:124
http://www.openwall.com/lists/oss-security/2013/03/06/5
http://www.oracle.com/technetwork/topics/security/bulletinjul2015-2511963.html
http://www.ruby-lang.org/en/news/2013/02/22/rexml-dos-2013-02-22/ Vendor Advisory
http://www.securityfocus.com/bid/58141
http://www.slackware.com/security/viewer.php?l=slackware-security&y=2013&m=slackware-security.426862
http://www.ubuntu.com/usn/USN-1780-1
https://bugzilla.redhat.com/show_bug.cgi?id=914716
https://wiki.mageia.org/en/Support/Advisories/MGASA-2013-0092
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