Vulnerability identifier: #VU32851

Vulnerability risk: Medium

CVSSv3.1: 4.6 [CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2011-3348

CWE-ID: CWE-399

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Apache HTTP Server
Server applications / Web servers

Vendor: Apache Foundation

Description

The vulnerability allows a remote non-authenticated attacker to perform service disruption.

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.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Apache HTTP Server: 2.2.0 - 2.2.20

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External links
http://community.jboss.org/message/625307
http://httpd.apache.org/security/vulnerabilities_22.html#2.2.21
http://lists.apple.com/archives/security-announce/2012/Feb/msg00000.html
http://marc.info/?l=bugtraq&m=131731002122529&w=2
http://marc.info/?l=bugtraq&m=132033751509019&w=2
http://rhn.redhat.com/errata/RHSA-2012-0542.html
http://rhn.redhat.com/errata/RHSA-2012-0543.html
http://secunia.com/advisories/46013
http://support.apple.com/kb/HT5130
http://www.apache.org/dist/httpd/Announcement2.2.html
http://www.mandriva.com/security/advisories?name=MDVSA-2011:168
http://www.oracle.com/technetwork/topics/security/cpujuly2013-1899826.html
http://www.redhat.com/support/errata/RHSA-2011-1391.html
http://www.securityfocus.com/bid/49616
http://www.securitytracker.com/id?1026054
http://exchange.xforce.ibmcloud.com/vulnerabilities/69804
http://lists.apache.org/thread.html/8d63cb8e9100f28a99429b4328e4e7cebce861d5772ac9863ba2ae6f@%3Ccvs.httpd.apache.org%3E
http://lists.apache.org/thread.html/f7f95ac1cd9895db2714fa3ebaa0b94d0c6df360f742a40951384a53@%3Ccvs.httpd.apache.org%3E
http://lists.apache.org/thread.html/r57608dc51b79102f3952ae06f54d5277b649c86d6533dcd6a7d201f7@%3Ccvs.httpd.apache.org%3E
http://lists.apache.org/thread.html/rfbaf647d52c1cb843e726a0933f156366a806cead84fbd430951591b@%3Ccvs.httpd.apache.org%3E
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A14941
http://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A18154

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.