#VU16547 Infinite loop in HAProxy - CVE-2018-20103

Vulnerability identifier: #VU16547

Vulnerability risk: Low

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear]

CVE-ID: CVE-2018-20103

CWE-ID: CWE-835

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 cause DoS condition on the target system.

The vulnerability exists in the dns_read_name() function, as defined in the src/dns.c source code file due to an error when processing malicious input. A remote attacker can send a specially crafted packet that submits malicious input, make a compressed pointer point to itself trigger an infinite loop and cause the affected software to crash.

Mitigation
Update to version 1.18.15.

Vulnerable software versions

HAProxy: 1.0.0 - 1.0.2, 1.1.0 - 1.1.34, 1.2.0 - 1.2.18, 1.3.0 - 1.3.28.14, 1.4.0 - 1.4.27, 1.5.0 - 1.5.19, 1.6.0 - 1.6.14, 1.7.0 - 1.7.10, 1.8.0 - 1.8.14

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External links
https://www.haproxy.org/download/1.8/src/CHANGELOG

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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.