Vulnerability · Published Jun 27, 2025 · Assigned by GitHub_M
CVE-2025-53094ESPAsyncWebServer Vulnerable to CRLF Injection in AsyncWebHeader.cpp
High 8.7
In plain English
A high-severity security flaw in ESPAsyncWebServer from ESP32Async. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 37% of all known vulnerabilities).
Official description
ESPAsyncWebServer is an asynchronous HTTP and WebSocket server library for ESP32, ESP8266, RP2040 and RP2350. In versions up to and including 3.7.8, a CRLF (Carriage Return Line Feed) injection vulnerability exists in the construction and output of HTTP headers within `AsyncWebHeader.cpp`. Unsanitized input allows attackers to inject CR (`\r`) or LF (`\n`) characters into header names or values, leading to arbitrary header or response manipulation. Manipulation of HTTP headers and responses can enable a wide range of attacks, making the severity of this vulnerability high. A fix is available at pull request 211 and is expected to be part of version 3.7.9.
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| ESP32Async | ESPAsyncWebServer | <= 3.7.8 |
Weakness: CWE-93, CWE-113 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-87j8-6f7g-h8wh x_refsource_CONFIRM
- https://github.com/ESP32Async/ESPAsyncWebServer/pull/211 x_refsource_MISC
- https://github.com/ESP32Async/ESPAsyncWebServer/blob/1095dfd1ecf1a903aede29854232af1b24f089b1/src/AsyncWebHeader.cpp#L6-L32 x_refsource_MISC