An issue was discovered in Squid before 4.12 and 5.x before 5.0.3. Due to use of a potentially dangerous function, Squid and the default certificate validation helper are vulnerable to a Denial of Service when opening a TLS connection to an attacker-controlled server for HTTPS. This occurs because unrecognized error values are mapped to NULL, but later code expects that each error value is mapped to a valid error string.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Squid | Squid-cache | 3.1 (including) | 3.5.28 (including) |
| Squid | Squid-cache | 4.0 (including) | 4.12 (excluding) |
| Squid | Squid-cache | 5.0 (including) | 5.0.3 (excluding) |
| Red Hat Enterprise Linux 8 | RedHat | squid:4-8030020200828070549.30b713e6 | * |
| Squid | Ubuntu | trusty | * |
| Squid3 | Ubuntu | trusty | * |