CVE-2023-26138
About
All versions of the package drogonframework/drogon are vulnerable to CRLF Injection when untrusted user input is used to set request headers in the addHeader function. An attacker can add the \r\n (carriage return line feeds) characters and inject additional headers in the request sent.
Rainforest analyst review
The Drogon C++ web framework is vulnerable to CRLF injection in its addHeader function: when untrusted input is used to set a request header, an attacker can inject carriage-return/line-feed sequences and smuggle in additional headers. The impact is rated low on confidentiality and integrity and requires the affected path to process attacker-influenced input, so this is header manipulation and potential response-splitting rather than a direct takeover.
CRLF/header-injection issues are useful as ingredients, cache poisoning, response splitting, or manipulating downstream behavior, more than as standalone exploits, and they depend on the application actually passing user input into header-setting calls. There is no broad, unauthenticated mass-exploitation dynamic here; the risk is proportional to how a given application built on Drogon uses addHeader with untrusted data.
This is a dependency-and-usage question for us. Drogon is a framework compiled into applications, so we identify which services build on it and, more specifically, which of them feed user-controlled values into addHeader, that usage pattern, not mere presence of the framework, is what determines exposure. We rank it moderate and drive remediation through updating the dependency and sanitizing header inputs in the affected services.
References
Related CVEs
Frequently asked questions
What is CVE-2023-26138?
All versions of the package drogonframework/drogon are vulnerable to CRLF Injection when untrusted user input is used to set request headers in the addHeader function. An attacker can add the \r\n (carriage return line feeds) characters and inject additional headers in the request sent.
How severe is CVE-2023-26138?
CVE-2023-26138 carries a CVSS 3.1 base score of 5.4, rated medium. On the Rainforest Risk Index — which weighs the severity alongside how easy the flaw is to reach and how broad its impact is — it scores 58 out of 100, in the elevated band.
How is CVE-2023-26138 exploited?
According to the CVSS vector (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:N): attack vector Network, attack complexity Low, privileges required None, user interaction Required. Impact on confidentiality Low, integrity Low and availability None.
Which products are affected by CVE-2023-26138?
Public advisories list the following as affected: drogon. Check the references on this page for the exact versions each vendor confirms.
How do I fix CVE-2023-26138?
Apply the fix the vendor published — the references on this page link to the primary advisories and patches. When patching can't happen right away, reduce the exposure of the affected component and watch it for exploitation attempts. Rainforest customers see this vulnerability correlated to their own assets and prioritized by real exposure, not by score alone.
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