There is a LOW severity vulnerability affecting CPython, specifically the http.cookies standard library module.
When parsing cookies that contained backslashes for quoted characters in the cookie value, the parser would use an algorithm with quadratic complexity, resulting in excess CPU resources being used while parsing the value.
The product uses a regular expression with an inefficient, possibly exponential worst-case computational complexity that consumes excessive CPU cycles.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Python | Python | * | 3.12.5 (including) |
| Python | Python | 3.13.0-alpha0 (including) | 3.13.0-alpha0 (including) |
| Python | Python | 3.13.0-alpha1 (including) | 3.13.0-alpha1 (including) |
| Python | Python | 3.13.0-alpha2 (including) | 3.13.0-alpha2 (including) |
| Python | Python | 3.13.0-alpha3 (including) | 3.13.0-alpha3 (including) |
| Python | Python | 3.13.0-alpha4 (including) | 3.13.0-alpha4 (including) |
| Python | Python | 3.13.0-alpha5 (including) | 3.13.0-alpha5 (including) |
| Python | Python | 3.13.0-alpha6 (including) | 3.13.0-alpha6 (including) |
| Python | Python | 3.13.0-beta1 (including) | 3.13.0-beta1 (including) |
| Python | Python | 3.13.0-beta2 (including) | 3.13.0-beta2 (including) |
| Python | Python | 3.13.0-beta3 (including) | 3.13.0-beta3 (including) |
| Python | Python | 3.13.0-beta4 (including) | 3.13.0-beta4 (including) |
| Python | Python | 3.13.0-rc1 (including) | 3.13.0-rc1 (including) |
| Python2.7 | Ubuntu | esm-apps/focal | * |
| Python2.7 | Ubuntu | esm-apps/jammy | * |
| Python2.7 | Ubuntu | esm-infra/bionic | * |
| Python2.7 | Ubuntu | esm-infra/xenial | * |
| Python2.7 | Ubuntu | focal | * |
| Python2.7 | Ubuntu | jammy | * |
| Python2.7 | Ubuntu | trusty/esm | * |
| Python3.10 | Ubuntu | jammy | * |
| Python3.12 | Ubuntu | noble | * |
| Python3.12 | Ubuntu | upstream | * |
| Python3.13 | Ubuntu | upstream | * |
| Python3.5 | Ubuntu | esm-infra/xenial | * |
| Python3.5 | Ubuntu | trusty/esm | * |
| Python3.8 | Ubuntu | focal | * |
Attackers can create crafted inputs that
intentionally cause the regular expression to use
excessive backtracking in a way that causes the CPU
consumption to spike.