Threat Encyclopedia

Memory Allocation, Out of Bounds Read, Integer Overflow, HTTP Request Smuggling, Information Disclosure, and Insufficient Verification of Data Authenticity Vulnerabilities for Apache HTTP Server


Apache HTTP Server 2.4.53 and earlier if configured to do transformations with mod_sed in contexts where the input to mod_sed may be very large, mod_sed may make excessively large memory allocations and trigger an abor, also a malicious request to a lua script that calls r:parsebody(0) may cause a denial of service due to no default limit on possible input size. HTTP Request Smuggling vulnerability exists in mod_proxy_ajp of Apache HTTP Server, which allows an attacker to smuggle requests to the AJP server it forwards requests to. A read beyond bounds when configured to process requests with the mod_isapi module is also seen. An integer overflow vulnerability is also seen with the ap_rwrite() function where an attacker can cause the server to reflect very large input using ap_rwrite() or ap_rputs(), such as with mod_luas r:puts() function. Modules compiled and distributed separately from Apache HTTP Server that use the 'ap_rputs' function and may pass it a very large (INT_MAX or larger) string must be compiled against current headers to resolve the issue. Integer oveflow can also be triggered when ap_strcmp_match() is provided with an extremely large input buffer. While no code distributed with the server can be coerced into such a call, third-party modules or lua scripts that use ap_strcmp_match() may hypothetically be affected. Insufficient Verification of Data Authenticity due to X-Forwarded-* headers not being sent to the origin server based on client side Connection header hop-by-hop mechanism. This may be used to bypass IP based authentication on the origin server/application. Exposing information because r:wsread() that point past the end of the storage allocated for the buffer.

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HTTP Server

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