Описание
urllib3 is an HTTP client library for Python. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. urllib3 can perform decoding or decompression based on the HTTP Content-Encoding header (e.g., gzip, deflate, br, or zstd). When using the streaming API, the library decompresses only the necessary bytes, enabling partial content consumption. Starting in version 1.22 and prior to version 2.6.3, for HTTP redirect responses, the library would read the entire response body to drain the connection and decompress the content unnecessarily. This decompression occurred even before any read methods were called, and configured read limits did not restrict the amount of decompressed data. As a result, there was no safeguard against decompression bombs. A malicious server could exploit this to trigger excessive resource consumption on the client. Applications and libraries are affected when they stream content from untrusted sources by setting preload_content=False when they do not disable redirects. Users should upgrade to at least urllib3 v2.6.3, in which the library does not decode content of redirect responses when preload_content=False. If upgrading is not immediately possible, disable redirects by setting redirect=False for requests to untrusted source.
A flaw was found in urllib3. When processing HTTP redirect responses during data streaming, the library automatically reads and decompresses the full response body without enforcing configured size limits. A malicious server can exploit this by serving an excessively compressed response, bypassing decompression bomb safeguards. This issue leads to high memory and processor consumption, resulting in a Denial of Service (DoS) on the client.
Отчет
Red Hat has rated this vulnerability as Important because an untrusted remote server can trigger severe CPU consumption and memory exhaustion on the client, leading to a denial of service without requiring authentication. This issue specifically affects scenarios where client applications stream content from untrusted endpoints while automatic redirect handling remains active, as redirect responses are uncompressed without enforcing stream limits. Environments that communicate only with trusted endpoints or configure requests to prevent automatic redirection are not susceptible to this attack vector.
Затронутые пакеты
| Платформа | Пакет | Состояние | Рекомендация | Релиз |
|---|---|---|---|---|
| Assisted Installer for Red Hat OpenShift Container Platform 2 | assisted/agent-preinstall-image-builder-rhel9 | Not affected | ||
| Assisted Installer for Red Hat OpenShift Container Platform 2 | rhai/assisted-installer-agent-rhel9 | Not affected | ||
| Assisted Installer for Red Hat OpenShift Container Platform 2 | rhai/assisted-installer-controller-rhel9 | Not affected | ||
| Assisted Installer for Red Hat OpenShift Container Platform 2 | rhai/assisted-installer-rhel9 | Not affected | ||
| Confidential Compute Attestation | build-of-trustee/trustee-rhel9 | Not affected | ||
| Confidential Compute Attestation | confidential-compute-attestation-tech-preview/trustee-rhel9 | Not affected | ||
| Confidential Compute Attestation | openshift-sandboxed-containers/osc-cloud-api-adaptor-rhel9 | Not affected | ||
| Confidential Compute Attestation | openshift-sandboxed-containers/osc-monitor-rhel9 | Not affected | ||
| Confidential Compute Attestation | openshift-sandboxed-containers/osc-podvm-builder-rhel9 | Not affected | ||
| Confidential Compute Attestation | openshift-sandboxed-containers/osc-podvm-payload-rhel9 | Not affected |
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Дополнительная информация
Статус:
EPSS
7.5 High
CVSS3
Связанные уязвимости
urllib3 is an HTTP client library for Python. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. urllib3 can perform decoding or decompression based on the HTTP `Content-Encoding` header (e.g., `gzip`, `deflate`, `br`, or `zstd`). When using the streaming API, the library decompresses only the necessary bytes, enabling partial content consumption. Starting in version 1.22 and prior to version 2.6.3, for HTTP redirect responses, the library would read the entire response body to drain the connection and decompress the content unnecessarily. This decompression occurred even before any read methods were called, and configured read limits did not restrict the amount of decompressed data. As a result, there was no safeguard against decompression bombs. A malicious server could exploit this to trigger excessive resource consumption on the client. Applicat...
urllib3 is an HTTP client library for Python. urllib3's streaming API is designed for the efficient handling of large HTTP responses by reading the content in chunks, rather than loading the entire response body into memory at once. urllib3 can perform decoding or decompression based on the HTTP `Content-Encoding` header (e.g., `gzip`, `deflate`, `br`, or `zstd`). When using the streaming API, the library decompresses only the necessary bytes, enabling partial content consumption. Starting in version 1.22 and prior to version 2.6.3, for HTTP redirect responses, the library would read the entire response body to drain the connection and decompress the content unnecessarily. This decompression occurred even before any read methods were called, and configured read limits did not restrict the amount of decompressed data. As a result, there was no safeguard against decompression bombs. A malicious server could exploit this to trigger excessive resource consumption on the client. Application
urllib3 vulnerable to decompression-bomb safeguard bypass when following HTTP redirects (streaming API)
urllib3 is an HTTP client library for Python. urllib3's streaming API ...
EPSS
7.5 High
CVSS3