#VU4171 Memory corruption in Squid - CVE-2016-2570

Vulnerability identifier: #VU4171

Vulnerability risk: Low

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

CVE-ID: CVE-2016-2570

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

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

Vendor: Squid-cache.org

Description
The vulnerability allows a remote attacker to cause DoS condition on the target system.

The weakness exists in the Edge Side Includes (ESI) parser due to improper checking of buffer limits during XML parsing. A remote attacker can use a specially crafted XML document, related to esi/CustomParser.cc and esi/CustomParser.h, as demonstrated by a crafted HTTP Vary header, trigger assertion failure and daemon exit and cause the service to crash.

Mitigation
Install update from vendor's website.

Vulnerable software versions

Squid: 3.1.0.1 - 3.5.15, 4.0.1 - 4.0.6

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External links
https://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-2018_1.patch
https://www.squid-cache.org/Versions/v4/changesets/SQUID-2018_2.patch

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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.