#VU26549 Heap-based buffer overflow in HAProxy - CVE-2020-11100

Vulnerability identifier: #VU26549

Vulnerability risk: High

CVSSv4.0: 8.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2020-11100

CWE-ID: CWE-122

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 attacker to execute arbitrary code on the target system.

The vulnerability exists due to a boundary error when processing HTTP/2 requests within the hpack_dht_insert() function in hpack-tbl.c (HPACK decoder). A remote attacker can send a specially crafted HTTP/2 request to the affected HAProxy, trigger heap-based buffer overflow and execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

HAProxy: 1.8.0 - 1.8.24, 1.9.0 - 1.9.14, 2.0.0 - 2.0.13, 2.1.0 - 2.1.3

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External links
https://www.haproxy.org
https://bugzilla.redhat.com/show_bug.cgi?id=1819111
https://git.haproxy.org/?p=haproxy.git;a=commit;h=5dfc5d5cd0d2128d77253ead3acf03a421ab5b88
https://lists.debian.org/debian-security-announce/2020/msg00052.html
https://www.haproxy.org/download/2.1/src/CHANGELOG
https://www.mail-archive.com/haproxy@formilux.org/msg36876.html

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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.