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Vulnerabilities

Vulnerability · CVE-2011-3348

The mod_proxy_ajp module in the Apache HTTP Server before 2.2.21, when used with mod_proxy_balancer in certain configurations, allows remote attackers to cause a denia…

Published Sep 20, 2011 · catalog updated Jun 16, 2026 · http server

Last checked Nov 7, 2026. A connected source was read within the last 7 days.

Check this week

CVE-2011-3348 is not in CISA KEV. FIRST estimates a 22.38% chance of exploitation in the next 30 days. Check whether you run http server.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.

Same product and reporting

Severity
Medium4.3
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
22.38%
Remediation
Version ranges on file
Affected products
cpe apache/http server · cpe redhat/jboss enterprise web server

The mod_proxy_ajp module in the Apache HTTP Server before 2.2.21, when used with mod_proxy_balancer in certain configurations, allows remote attackers to cause a denial of service (temporary "error state" in the backend server) via a malformed HTTP request.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • cpe apache/http server>= 2.2.12, <= 2.2.20
  • cpe redhat/jboss enterprise web server1.0.0

How to fix CVE-2011-3348

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

CVE-2011-3348 is not in CISA KEV. FIRST estimates a 22.38% chance of exploitation in the next 30 days. Check whether you run http server.

Which versions are affected?

Compare what you have installed with apache/http server >= 2.2.12, <= 2.2.20; redhat/jboss enterprise web server 1.0.0. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

CWE-400: Uncontrolled Resource Consumption. EPSS 22.38%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Apache HTTP Server security

Code

The project this record applies to. Exploit listings stay in References.

No public source repository is identified for this product.

Timeline

Detection, updates, and resolution for this record.

  1. Sep 20, 2011 · Monitored products — critical

    Detected

    The mod_proxy_ajp module in the Apache HTTP Server before 2.2.21, when used with mod_proxy_balancer in certain configurations, allows remote attackers to cause a denial of service (temporary "error state" in the backend server) via a malformed HTTP request.

  2. Jun 16, 2026 · Monitored products — critical

    Updated

    The mod_proxy_ajp module in the Apache HTTP Server before 2.2.21, when used with mod_proxy_balancer in certain configurations, allows remote attackers to cause a denial of service (temporary "error state" in the backend server) via a malformed HTTP request.

Sources

  • CVE.orgVulnerability recordCVE-2011-3348

    Official CVE identifier

    cve.org
  • Monitored products — criticalVendor advisoryCVE-2011-3348

    The mod_proxy_ajp module in the Apache HTTP Server before 2.2.21, when used with mod_proxy_balancer in certain configurations, allows remote attackers to cause a denial of service (temporary "error state" in the backend server) via a malformed HTTP request.

    nvd.nist.gov

References

Freshness

Last verified in this catalog Nov 7, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.

  • CVE.orgNov 4, 2026
  • Monitored products — criticalNov 4, 2026