The (1) ntlm_fetch_string and (2) ntlm_get_string functions in Squid 2.5.6 and earlier, with NTLM authentication enabled, allow remote attackers to cause a denial of service (application crash) via an NTLMSSP packet that causes a negative value to be passed to memcpy.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A10489
https://exchange.xforce.ibmcloud.com/vulnerabilities/17218
http://www1.uk.squid-cache.org/squid/Versions/v2/2.5/bugs/#squid-2.5.STABLE6-ntlm_fetch_string
http://www.trustix.org/errata/2004/0047/
http://www.squid-cache.org/bugs/show_bug.cgi?id=1045
http://www.securityfocus.com/bid/11098
http://www.mandriva.com/security/advisories?name=MDKSA-2004:093