CVE-2025-46728
Description
A flaw was found in cpp-httplib. This vulnerability allows for denial of service via oversized HTTP requests when using chunked transfer encoding or missing Content-Length headers, leading to uncontrolled memory allocation and potential server crash.
Statement
Red Hat Product Security has determined that this vulnerability does not affect any currently supported Red Hat product. This assessment may evolve based on further analysis and discovery. For more information about this vulnerability and the products it affects, please see the linked references.
Mitigation
Short-term workaround through a Reverse Proxy: If updating the library immediately is not feasible, deploy a reverse proxy, such as Nginx or HAProxy, in front of the cpp-httplib application. Configure the proxy to enforce maximum request body size limits, thereby stopping excessively large requests before they reach the vulnerable library code.
Code fix. Enforce limits during parsing. If the limit is exceeded at any point during reading, the connection should be terminated immediately (e.g., by returning an error or closing the stream).
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
If an attacker can trigger the allocation of the limited resources, but the number or size of the resources is not controlled, then the most common result is denial of service. This would prevent valid users from accessing the product, and it could potentially have an impact on the surrounding environment, i.e., the product may slow down, crash due to unhandled errors, or lock out legitimate users. For example, a memory exhaustion attack against an application could slow down the application as well as its host operating system.
Access Control,Other
Technical Impact: Bypass Protection Mechanism; Other
In some cases it may be possible to force the product to "fail open" in the event of resource exhaustion. The state of the product -- and possibly the security functionality - may then be compromised.
Frequently Asked Questions
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