Vulnerability identifier: #VU32659

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-2013-2175

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
HAProxy
Server applications / IDS/IPS systems, Firewalls and proxy servers

Vendor: HAProxy

Description

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

HAProxy 1.4 before 1.4.24 and 1.5 before 1.5-dev19, when configured to use hdr_ip or other "hdr_*" functions with a negative occurrence count, allows remote attackers to cause a denial of service (negative array index usage and crash) via an HTTP header with a certain number of values, related to the MAX_HDR_HISTORY variable.

Mitigation
Install update from vendor's website.

Vulnerable software versions

HAProxy: 1.1.4, 1.3.11.4, 1.4 - 1.4.23

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External links
http://marc.info/?l=haproxy&m=137147915029705&w=2
http://rhn.redhat.com/errata/RHSA-2013-1120.html
http://rhn.redhat.com/errata/RHSA-2013-1204.html
http://secunia.com/advisories/54344
http://www.debian.org/security/2013/dsa-2711
http://www.ubuntu.com/usn/USN-1889-1
http://bugzilla.redhat.com/show_bug.cgi?id=974259

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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.