Excessive read buffering DoS in http.client

Vulnerability Description

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.

References

• https://github.com/python/cpython/issues/119451
• https://github.com/python/cpython/pull/119454
• https://github.com/python/cpython/commit/4ce27904b597c77d74dd93f2c912676021a99155
• https://github.com/python/cpython/commit/5a4c4a033a4a54481be6870aa1896fad732555b5
• https://mail.python.org/archives/list/security-announce@python.org/thread/OQ6G7MKRQIS3OAREC3HNG3D2DPOU34XO/
• https://github.com/python/cpython/commit/289f29b0fe38baf2d7cb5854f4bb573cc34a6a15
• https://github.com/python/cpython/commit/14b1fdb0a94b96f86fc7b86671ea9582b8676628
• https://github.com/python/cpython/commit/5dc101675fd22918facbbe0fecdc821502beaaf0
• https://github.com/python/cpython/commit/afc40bdd3dd71f343fd9016f6d8eebbacbd6587c