Apache Httpd 2.4.18 Vulnerability -

In Apache versions 2.4.17 through 2.4.18, the mod_cgid module failed to properly handle the termination of CGI scripts. The vulnerability allowed a remote attacker to cause a Denial of Service (DoS). Specifically, if a CGI script was killed or terminated abruptly, the module might fail to correctly close the pipe or socket connection to that script. This resulted in a "zombie" process or a resource leak that could eventually exhaust the server’s available process slots or file descriptors.

| CVE ID | Component | Issue | Impact | |--------|-----------|-------|--------| | CVE-2016-8740 | mod_http2 | Incorrect handling of Host header | HTTP/2 downgrade attack | | CVE-2016-8743 | mod_http2 | Null pointer dereference | DoS | | CVE-2017-9789 | mod_http2 | Read-after-free | Memory leak / crash | | CVE-2017-9798 | OptionsBleed | Optionsbleed – memory leak from Limit directive | Information disclosure | | CVE-2017-15710 | mod_authnz_ldap | Buffer overread | Crash or info leak | apache httpd 2.4.18 vulnerability

: Attackers can perform a padding oracle attack to decrypt session cookies or even modify them to include attacker-specified data. This could lead to session hijacking or unauthorized access. Severity : High (CVSS 7.5). 3. Privilege Escalation (CVE-2019-0211) In Apache versions 2

Furthermore, the architecture of 2.4.18 relied heavily on the Apache Portable Runtime (APR). Vulnerabilities in the underlying APR library often manifest as vulnerabilities in the httpd server itself. In the 2015-2016 window, APR vulnerabilities regarding integer overflows and memory corruption were a concurrent concern, meaning a secure httpd binary required a secure underlying library—a dependency often overlooked in manual compilations. This resulted in a "zombie" process or a