When reading an HTTP response from a server, if no read amount is specified, the default behavior will be to use Content-Length. This allows a malicious server to cause the client to read large amounts of data into memory, potentially causing OOM or other DoS.
Weakness
The product does not properly control the allocation and maintenance of a limited resource.
Affected Software
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Python | Python | * | 3.13.11 (excluding) |
| Python | Python | 3.14.0 (including) | 3.14.0 (including) |
| Python | Python | 3.15.0-alpha1 (including) | 3.15.0-alpha1 (including) |
| Python | Python | 3.15.0-alpha2 (including) | 3.15.0-alpha2 (including) |
| Red Hat Enterprise Linux 10 | RedHat | python3.12-0:3.12.12-3.el10_1 | * |
| Red Hat Enterprise Linux 10.0 Extended Update Support | RedHat | python3.12-0:3.12.9-2.el10_0.6 | * |
| Red Hat Enterprise Linux 8 | RedHat | python3.11-0:3.11.13-4.el8_10 | * |
| Red Hat Enterprise Linux 8 | RedHat | python3.12-0:3.12.12-2.el8_10 | * |
| Red Hat Enterprise Linux 8.8 Telecommunications Update Service | RedHat | python3.11-0:3.11.2-2.el8_8.7 | * |
| Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions | RedHat | python3.11-0:3.11.2-2.el8_8.7 | * |
| Red Hat Enterprise Linux 9 | RedHat | python3.12-0:3.12.12-4.el9_7 | * |
| Red Hat Enterprise Linux 9 | RedHat | python3.11-0:3.11.13-5.el9_7 | * |
| Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions | RedHat | python3.11-0:3.11.2-2.el9_2.9 | * |
| Red Hat Enterprise Linux 9.4 Extended Update Support | RedHat | python3.11-0:3.11.7-1.el9_4.10 | * |
| Red Hat Enterprise Linux 9.6 Extended Update Support | RedHat | python3.11-0:3.11.11-2.el9_6.4 | * |
| Red Hat Discovery 2 | RedHat | discovery/discovery-server-rhel9:sha256:519d4fe184cebe5152f840e9f609fa4705590656ac9bcace2e2e17622ab7e6a8 | * |
| Red Hat Update Infrastructure 5 | RedHat | rhui5/installer-rhel9:sha256:48cf7cf48dfadb17f9357bf1894a5d0393551a893faa8b0ea0e11fe1ffed497f | * |
| Red Hat Update Infrastructure 5 | RedHat | rhui5/rhua-rhel9:sha256:df709663b581b740006c6ea4b297978932874eade1563c3952e0594e926aa5f8 | * |
| Python3.10 | Ubuntu | jammy | * |
| Python3.11 | Ubuntu | esm-apps/jammy | * |
| Python3.11 | Ubuntu | jammy | * |
| Python3.12 | Ubuntu | noble | * |
| Python3.13 | Ubuntu | plucky | * |
| Python3.13 | Ubuntu | questing | * |
| Python3.14 | Ubuntu | questing | * |
| Python3.8 | Ubuntu | esm-apps/bionic | * |
| Python3.8 | Ubuntu | esm-infra/focal | * |
| Python3.9 | Ubuntu | esm-apps/focal | * |
Potential Mitigations
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.
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/147.html
- https://cwe.mitre.org/data/definitions/227.html
- https://cwe.mitre.org/data/definitions/492.html
References
- https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628
- https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15
- https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155
- https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5
- https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0
- https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c
- https://github.com/python/cpython/issues/119451
- https://github.com/python/cpython/pull/119454
- https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/