CVE-2025-53007
arduino-esp32 vulnerable to CRLF injection in WebServer.cpp
No known exploitation. EPSS puts it in the 40th percentile. No fix published yet.
What to do
No fixed build or workaround is published yet. Limit exposure and watch for a patch.
- Espressif Arduino-esp32Affected: < 3.2.1Upgrade to: not statedAffected: >= 3.3.0-alpha1, < 3.3.0-RC1Upgrade to: not statedStated by: CVE record
Versions as the sources state them. Full version matrix after sign-in
What it is
From the CVE record
arduino-esp32 provides an Arduino core for the ESP32. Versions prior to 3.3.0-RC1 and 3.2.1 contain a HTTP Response Splitting vulnerability. The `sendHeader` function takes arbitrary input for the HTTP header name and value, concatenates them into an HTTP header line, and appends this to the outgoing HTTP response headers. There is no validation or sanitization of the `name` or `value` parameters before they are included in the HTTP response. If an attacker can control the input to `sendHeader` (either directly or indirectly), they could inject carriage return (`\r`) or line feed (`\n`) characters into either the header name or value. This could allow the attacker to inject additional headers, manipulate the structure of the HTTP response, potentially inject an entire new HTTP response (HTTP Response Splitting), and/or ause header confusion or other HTTP protocol attacks. Versions 3.3.0-RC1 and 3.2.1 contain a fix for the issue.
In plain language
No plain-language summary for this CVE yet.
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
No public exploit or proof of concept found in the sources we track.
- EPSS
0.5% chance of exploitation activity in the next 30 days, which ranks it in the 40th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
3 events over 0 days, from the signal feeds we watch.
- Publishedweakness classified, record updated
Affected products
Technical detail
Weaknesses
Sources
References in the record
- github.com/espressif/arduino-esp32/security/advisories/GHSA-5476-9jjq-563m
- github.com/espressif/arduino-esp32/commit/21640ac82a1bb5efa8cf0b3841be1ac80add6785
- github.com/espressif/arduino-esp32/blob/9e61fa7e4bce59c05cb17c15b11b53b9bafca077/libraries/WebServer/src/WebServer.cpp
And 1 more reference. See all after sign-in
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