CVE-2016-2390 Denial of service in n/a
Remote attackers can crash the Squid proxy server by sending plaintext HTTP messages if it is built with OpenSSL support.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2016-2390?
CVE-2016-2390 is a medium-severity denial of service vulnerability in Squid-Cache Squid, published on 19 Apr 2016. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
The FwdState::connectedToPeer method in FwdState.cc in Squid before 3.5.14 and 4.0.x before 4.0.6 does not properly handle SSL handshake errors when built with the --with-openssl option, which allows remote attackers to cause a denial of service (application crash) via a plaintext HTTP message.
Weakness: CWE-20
Which versions are affected by CVE-2016-2390?
It affects 1 product.
Products include Squid-Cache Squid.
How do I fix CVE-2016-2390?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2016-2390 being exploited?
There is no known exploitation of CVE-2016-2390 in the wild and no public exploit code.
Other vulnerabilities in Squid-Cache Squid
- CVE-2025-62168 Squid vulnerable to information disclosure via authentication credential leakage in error handling
- CVE-2025-54574 Squid's URN Handling can lead to Buffer Overflow
- CVE-2026-33526 Squid vulnerable to Denial of Service in ICP Request handling
- CVE-2026-32748 Squid has Denial of Service in ICP Response handling
- CVE-2023-50269 SQUID-2023:10 Denial of Service in HTTP Request parsing
Sources
Also known as DEBIAN-CVE-2016-2390, GHSA-qg6v-rjmq-c5vh.