httplib2 is a comprehensive HTTP client library for Python. In httplib2 before version 0.19.0, a malicious server which responds with long series of xa0 characters in the www-authenticate header may cause Denial of Service (CPU burn while parsing header) of the httplib2 client accessing said server. This is fixed in version 0.19.0 which contains a new implementation of auth headers parsing using the pyparsing library.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Httplib2 | Httplib2_project | * | 0.19.0 (excluding) |
| Red Hat OpenStack Platform 16.1 | RedHat | python-httplib2-0:0.13.1-2.el8ost | * |
| Python-httplib2 | Ubuntu | bionic | * |
| Python-httplib2 | Ubuntu | esm-infra-legacy/trusty | * |
| Python-httplib2 | Ubuntu | esm-infra/bionic | * |
| Python-httplib2 | Ubuntu | esm-infra/focal | * |
| Python-httplib2 | Ubuntu | esm-infra/xenial | * |
| Python-httplib2 | Ubuntu | focal | * |
| Python-httplib2 | Ubuntu | groovy | * |
| Python-httplib2 | Ubuntu | hirsute | * |
| Python-httplib2 | Ubuntu | impish | * |
| Python-httplib2 | Ubuntu | jammy | * |
| Python-httplib2 | Ubuntu | kinetic | * |
| Python-httplib2 | Ubuntu | precise/esm | * |
| Python-httplib2 | Ubuntu | trusty | * |
| Python-httplib2 | Ubuntu | trusty/esm | * |
| Python-httplib2 | Ubuntu | upstream | * |
| Python-httplib2 | Ubuntu | xenial | * |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.