#VU23084 CRLF injection in HAProxy - CVE-2019-19330

Vulnerability identifier: #VU23084

Vulnerability risk: Medium

CVSSv4.0: 2.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2019-19330

CWE-ID: CWE-93

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 perform spoofing attack.

The vulnerability exists due to insufficient validation of user-supplied input when processing CRLF and NUL character in the HTTP request, while converting headers from HTTP/2 to HTTP/1. A remote attacker can send a specially crafted HTTP/2 request to the HAProxy and inject arbitrary HTTP headers. Successful exploitation of the vulnerability may allow an attacker to bypass certain security restrictions or perform spoofing attacks.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

HAProxy: 2.0.0 - 2.0.9

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External links
https://git.haproxy.org/?p=haproxy.git;a=commit;h=146f53ae7e97dbfe496d0445c2802dd0a30b0878
https://git.haproxy.org/?p=haproxy.git;a=commit;h=54f53ef7ce4102be596130b44c768d1818570344
https://git.haproxy.org/?p=haproxy-2.0.git;a=commit;h=ac198b92d461515551b95daae20954b3053ce87e
https://tools.ietf.org/html/rfc7540#section-10.3

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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.