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CVE-2011-4858

79
FAUCET Score

CVE-2011-4858 describes a denial-of-service vulnerability in Apache Tomcat versions before 5.5.35, 6.0.35, and 7.0.23. This flaw allows remote attackers to consume excessive CPU resources by sending crafted form parameters that exploit predictable hash collisions. With a CVSS score of 5.0 and a FAUCET Risk Score of 99/100, this vulnerability is easily exploitable over the network with low complexity and no authentication, leading to a denial of service. While not on the KEV catalog, a Metasploit module exists for hash table collisions, indicating exploitability, though there is no evidence of active exploitation or significant community discussion.

Impacted Technologies

VendorProductVersion(s)CPE
5.5.35CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:5.5.35:*:*:*:*:*:*:*
6.0.0CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:6.0.0:*:*:*:*:*:*:*
6.0.1CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:6.0.1:*:*:*:*:*:*:*
6.0.2CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:6.0.2:*:*:*:*:*:*:*
6.0.3CPE matchmatch criteria
cpe:2.3:a:apache:tomcat:6.0.3:*:*:*:*:*:*:*

CVSS Data

CVSS version used by this source: 2.0

5.0MEDIUM

AV:N/AC:L/Au:N/C:N/I:N/A:P

Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Exploitability Score
10.0
Impact Score
2.9
CvssVersion
2.0

Exploit Intelligence

EPSS Score
80.32%
Probability of exploitation in next 30 days
EPSS Percentile
99.6%
Percentile rank of EPSS score among Peer Group
As of 2026-07-27
Model: v2026.06.15
Metasploit: Hashtable Collisions · Dec 28, 2011
ExploitDB: EDB-2012 · Jul 15, 2006
This CVE's current EPSS score of 0.8032 is in the 100th percentile among its peer group of 23,701 CVEs.

Social Chatter

The average CVE in this peer group has 0.0 Twitter, 0.0 Reddit, 0.1 Bluesky, 0.0 Mastodon, and 0.4 GitHub mentions.

Media Mentions

No media coverage found for this CVE.

The average CVE in this peer group has 0.0 InfoSec Media, 0.0 Vendor Blog, and 0.0 Security Researcher mentions.

Remediation

Patch Available

Vendor Patches (25)

mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 5.5.35
mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 6.0.35
mavenpatch availablevia ghsa
Product: org.apache.tomcat:tomcatFixed in: 7.0.23
redhatpatch availablevia redhat_api
Product: JBoss Communications Platform 5.1
View patch
redhatpatch availablevia redhat_api
Product: JBoss Enterprise BRMS Platform 5.1
View patch
redhatpatch availablevia redhat_api
Product: JBEWP 5 for RHEL 5Fixed in: jbossweb-0:2.1.12-3_patch_03.2.ep5.el5
View patch
redhatpatch availablevia redhat_api
Product: JBEWP 5 for RHEL 6Fixed in: jbossweb-0:2.1.12-3_patch_03.2.ep5.el6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 5Fixed in: tomcat5-0:5.5.23-0jpp.31.el5_8
View patch
redhatpatch availablevia redhat_api
Product: Red Hat Enterprise Linux 6Fixed in: tomcat6-0:6.0.24-36.el6_2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Application Platform 4.3
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Application Platform 5.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Application Platform 5 for RHEL 4Fixed in: jbossweb-0:2.1.12-3_patch_03.2.ep5.el4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Application Platform 5 for RHEL 5Fixed in: jbossweb-0:2.1.12-3_patch_03.2.ep5.el5
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Application Platform 5 for RHEL 6Fixed in: jbossweb-0:2.1.12-3_patch_03.2.ep5.el6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Web Server 1 for RHEL 5Fixed in: tomcat5-0:5.5.33-27_patch_07.ep5.el5
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Web Server 1 for RHEL 5Fixed in: tomcat6-0:6.0.32-24_patch_07.ep5.el5
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Web Server 1 for RHEL 6Fixed in: tomcat5-0:5.5.33-28_patch_07.ep5.el6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Enterprise Web Server 1 for RHEL 6Fixed in: tomcat6-0:6.0.32-24_patch_07.ep5.el6
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Operations Network 2.4
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Operations Network 3.0
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Portal 4.3
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Portal 5.2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss SOA Platform 5.2
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Platform 5.1
View patch
redhatpatch availablevia redhat_api
Product: Red Hat JBoss Web Server 1.0
View patch

Vendor Advisories (2)

mavenGHSA-wr3m-gw98-mc3jmedium

Improper Input Validation in Apache Tomcat

May 14, 2022
redhatCVE-2011-4858Moderate

tomcat: hash table collisions CPU usage DoS (oCERT-2011-003)

Dec 28, 2011

References

mail-archives.apache.org / mod_mbox/tomcat-announce/201112.mbox/%3c4EFB9800.5010106%40apache.org%3e
marc.info
marc.info
marc.info
rhn.redhat.com / errata/RHSA-2012-0074.html
rhn.redhat.com / errata/RHSA-2012-0075.html
rhn.redhat.com / errata/RHSA-2012-0076.html
rhn.redhat.com / errata/RHSA-2012-0077.html
rhn.redhat.com / errata/RHSA-2012-0078.html
rhn.redhat.com / errata/RHSA-2012-0089.html
rhn.redhat.com / errata/RHSA-2012-0325.html
rhn.redhat.com / errata/RHSA-2012-0406.html
bugzilla.redhat.com / show_bug.cgi
secunia.com / advisories/48549
secunia.com / advisories/48790
secunia.com / advisories/48791
secunia.com / advisories/54971
secunia.com / advisories/55115
github.com / FireFart/HashCollision-DOS-POC/blob/master/HashtablePOC.py
oval.cisecurity.org / repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18886
tomcat.apache.org / tomcat-7.0-doc/changelog.html
debian.org / security/2012/dsa-2401
kb.cert.org / vuls/id/903934
US Government Resource
nruns.com / _downloads/advisory28122011.pdf
ocert.org / advisories/ocert-2011-003.html
securityfocus.com / bid/51200