CVE-2018-1000027: Null Pointer Dereference
Due to incorrect pointer handling, Squid versions 3.x (prior to 3.5.27) and 4.x (prior to 4.0.23) are vulnerable to a denial of service attack when processing HTTP messages or downloading intermediate CA certificates. This problem allows a remote client delivering certain HTTP requests in conjunction with certain trusted server responses to trigger a denial of service for all clients accessing the Squid service.
Upstream Advisory: http://www.squid-cache.org/Advisories/SQUID-20182.txt
Upstream Patches: http://www.squid-cache.org/Versions/v3/3.5/changesets/SQUID-20182.patch http://www.squid-cache.org/Versions/v4/changesets/SQUID-20182.patch
Other sources
The Squid Software Foundation Squid HTTP Caching Proxy version prior to version 4.0.23 contains a NULL Pointer Dereference vulnerability in HTTP Response X-Forwarded-For header processing that can result in Denial of Service to all clients of the proxy. This attack appear to be exploitable via Remote HTTP server responding with an X-Forwarded-For header to certain types of HTTP request. This vulnerability appears to have been fixed in 4.0.23 and later.
— Launchpad
Affected Software
Remediation
Patch Available
Event History
Frequently Asked Questions
What is the vulnerability ID of this Squid software vulnerability?
The vulnerability ID of this Squid software vulnerability is CVE-2018-1000027.
What is the severity of CVE-2018-1000027?
The severity of CVE-2018-1000027 is high with a score of 7.5.
What is the affected software version for CVE-2018-1000027?
The affected software versions for CVE-2018-1000027 are Squid HTTP Caching Proxy versions prior to version 4.0.23.
What is the impact of CVE-2018-1000027?
CVE-2018-1000027 can result in Denial of Service to all clients of the proxy.
How can I fix CVE-2018-1000027?
To fix CVE-2018-1000027, upgrade to Squid HTTP Caching Proxy version 4.0.23 or higher.