When a HTTP/2 stream was reset (RST frame) by a client, there was a time window were the request's memory resources were not reclaimed immediately. Instead, de-allocation was deferred to connection close. A client could send new requests and resets, keeping the connection busy and open and causing the memory footprint to keep on growing. On connection close, all resources were reclaimed, but the process might run out of memory before that.
This was found by the reporter during testing of CVE-2023-44487 (HTTP/2 Rapid Reset Exploit) with their own test client. During "normal" HTTP/2 use, the probability to hit this bug is very low. The kept memory would not become noticeable before the connection closes or times out.
Users are recommended to upgrade to version 2.4.58, which fixes the issue.
Some mod_proxy configurations on Apache HTTP Server versions 2.4.0 through 2.4.55 allow a HTTP Request Smuggling attack.
Configurations are affected when mod_proxy is enabled along with some form of RewriteRule
or ProxyPassMatch in which a non-specific pattern matches
some portion of the user-supplied request-target (URL) data and is then
re-inserted into the proxied request-target using variable
substitution. For example, something like:
RewriteEngine on
RewriteRule "^/here/(.*)" "http://example.com:8080/elsewhere?$1"; [P]
ProxyPassReverse /here/ http://example.com:8080/
Request splitting/smuggling could result in bypass of access controls in the proxy server, proxying unintended URLs to existing origin servers, and cache poisoning. Users are recommended to update to at least version 2.4.56 of Apache HTTP Server.
HTTP Response Smuggling vulnerability in Apache HTTP Server via mod_proxy_uwsgi. This issue affects Apache HTTP Server: from 2.4.30 through 2.4.55.
Special characters in the origin response header can truncate/split the response forwarded to the client.
A carefully crafted If: request header can cause a memory read, or write of a single zero byte, in a pool (heap) memory location beyond the header value sent. This could cause the process to crash.
This issue affects Apache HTTP Server 2.4.54 and earlier.
Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling') vulnerability in mod_proxy_ajp of Apache HTTP Server allows an attacker to smuggle requests to the AJP server it forwards requests to. This issue affects Apache HTTP Server Apache HTTP Server 2.4 version 2.4.54 and prior versions.
Prior to Apache HTTP Server 2.4.55, a malicious backend can cause the response headers to be truncated early, resulting in some headers being incorporated into the response body. If the later headers have any security purpose, they will not be interpreted by the client.
Heap-based buffer overflow in the fcgid_header_bucket_read function in fcgid_bucket.c in the mod_fcgid module before 2.3.9 for the Apache HTTP Server allows remote attackers to have an unspecified impact via unknown vectors.
The ModSecurity module before 2.7.4 for the Apache HTTP Server allows remote attackers to cause a denial of service (NULL pointer dereference, process crash, and disk consumption) via a POST request with a large body and a crafted Content-Type header.
Cross-site scripting (XSS) vulnerability in EMC RSA Authentication Agent 7.1 before 7.1.1 for Web for Internet Information Services, and 7.1 before 7.1.1 for Web for Apache, allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
EMC RSA Authentication API before 8.1 SP1, RSA Web Agent before 5.3.5 for Apache Web Server, RSA Web Agent before 5.3.5 for IIS, RSA PAM Agent before 7.0, and RSA Agent before 6.1.4 for Microsoft Windows use an improper encryption algorithm and a weak key for maintaining the stored data of the node secret for the SecurID Authentication API, which allows local users to obtain sensitive information via cryptographic attacks on this data.