Описание
undici vulnerable to downstream response desynchronization via retry interceptor
Impact
Undici's interceptors.retry() can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. Applications that use interceptors.retry() and forward upstream response headers and bodies downstream, for example proxy or gateway applications, may emit an invalid HTTP response with a stale Content-Length header. This can lead to downstream response desynchronization, connection hangs, or response corruption in clients or intermediaries that rely on the forwarded framing metadata.
A malicious or faulty upstream can respond to a range request with a 206 Partial Content response such as:
and then send only 99 bytes before closing the socket. interceptors.retry() can then retry with Range: bytes=99-99, receive the final byte, and deliver a 100-byte body to the application while the response headers still contain Content-Length: 300 from the first response.
The bug requires interceptors.retry() to be enabled, an upstream that returns a partial response with a mismatched framing header, and a downstream forwarder that does not remove or recalculate Content-Length.
Patches
Patched in undici v6.28.0, v7.29.0, and v8.9.0. Users should upgrade to one of these versions or later.
Workarounds
- Disable
interceptors.retry()for untrusted upstreams. - Remove or recalculate
Content-Lengthbefore forwarding a response body assembled or transformed by Undici.
Ссылки
- https://github.com/nodejs/undici/security/advisories/GHSA-8xcm-r25x-g524
- https://nvd.nist.gov/vuln/detail/CVE-2026-16728
- https://github.com/nodejs/undici/commit/1b5a5312c3a7d7a30c31bf0d000b39a8a2531e1c
- https://github.com/nodejs/undici/commit/2b3f749336d356bbbc50192f87f6cf7bc714721a
- https://github.com/nodejs/undici/commit/4a9dafb16ff43880cf590e6d9c2aeee25fbff6d7
- https://github.com/nodejs/undici/commit/4fd5a0c61e627f928b7003adc4ffe1e55ec63420
- https://github.com/nodejs/undici/commit/cba3a52ac2e7abcc4e656d82af8579ea82c2bb9e
- https://github.com/nodejs/undici/commit/e11a68ed4ff345c79402476f7a00d473443e318d
- https://hackerone.com/reports/3828685
- https://cna.openjsf.org/security-advisories.html
- https://github.com/nodejs/undici/releases/tag/v6.28.0
- https://github.com/nodejs/undici/releases/tag/v7.29.0
- https://github.com/nodejs/undici/releases/tag/v8.9.0
Пакеты
undici
< 6.28.0
6.28.0
undici
>= 7.0.0, < 7.29.0
7.29.0
undici
>= 8.0.0, < 8.9.0
8.9.0
Связанные уязвимости
undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is f...
undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is f...
undici's retry interceptor can deliver a response whose body length does not match the Content-Length header exposed to the application after a retry or resume of a partial response. In undici before 6.28.0, from 7.0.0 up to before 7.29.0, and from 8.0.0 up to before 8.9.0, a malicious or faulty upstream can return a partial response with a mismatched framing header, close the socket early, and have the retry interceptor assemble a body of a different length while the original Content-Length stays attached. Applications that use the retry interceptor and forward upstream headers and bodies downstream, such as proxies or gateways, may then emit an invalid HTTP response with a stale Content-Length, leading to downstream response desynchronization, connection hangs, or response corruption. Exploitation requires the retry interceptor enabled, an upstream returning a mismatched partial response, and a downstream forwarder that does not remove or recalculate Content-Length. The issue is fixe
undici's retry interceptor can deliver a response whose body length do ...