CVE-2025-53094CWE-113CWE-93

ESPAsyncWebServer Vulnerable to CRLF Injection in AsyncWebHeader.cpp

High · published June 27, 2025

CVSS v4.0
8.7
EPSS
0%
Percentile
36.2
In the wild
Unconfirmed
What it is

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.

The record
Technical detail
CVSS v4.0
8.7 · HIGH
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
EPSS
0.00430 · 36.2th percentile
Weaknesses
CWE-113 · Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Request/Response Splitting'); CWE-93 · Improper Neutralization of CRLF Sequences ('CRLF Injection')
Published
2025-06-27T19:57Z
EPSS history
Timeline
  • 27 JUN 19:57Z
    ESPAsyncWebServer Vulnerable to CRLF Injection in AsyncWebHeader.cpp
    cvelistv5