A race condition was found in modauthdigest when the web server was running in a threaded MPM configuration. It could allow a user with valid credentials to authenticate using another username, bypassing configured access control restrictions.
Apache HTTP Server, with MPM event, worker or prefork, code executing in less-privileged child processes or threads (including scripts executed by an in-process scripting interpreter) could execute code with the privileges of the parent process (usually root) by manipulating the scoreboard.
A flaw was found in HTTP/2 (modhttp2) connections in Apache HTTP Server httpd 2.4.17 to 2.4.37. A DoS can be triggered by sending request bodies in a slow loris way to plain resources, the h2 stream for that request unnecessarily occupied a server thread cleaning up that incoming data.
References: https://seclists.org/oss-sec/2019/q1/80 https://httpd.apache.org/security/vulnerabilities24.html
A vulnerability was found in Apache HTTP Server 2.4.34 to 2.4.38. When HTTP/2 was enabled for a http: host or H2Upgrade was enabled for h2 on a https: host, an Upgrade request from http/1.1 to http/2 that was not the first request on a connection could lead to a misconfiguration and crash. Server that never enabled the h2 protocol or that only enabled it for https: and did not set "H2Upgrade on" are unaffected by this issue.
In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 protocol.
Legion of the Bouncy Castle Java Cryptography APIs could allow a remote attacker to execute arbitrary code on the system, caused by an unsafe reflection flaw in XMSS/XMSS^MT private key deserialization. By using specially-crafted private key, an attacker could exploit this vulnerability to execute arbitrary code on the system.
Bouncy Castle BC 1.54 - 1.59, BC-FJA 1.0.0, BC-FJA 1.0.1 and earlier have a flaw in the Low-level interface to RSA key pair generator, specifically RSA Key Pairs generated in low-level API with added certainty may have less M-R tests than expected. This appears to be fixed in versions BC 1.60 beta 4 and later, BC-FJA 1.0.2 and later.
A bug exists in the way modssl handled client renegotiations. A remote attacker could send a carefully crafted request that would cause modssl to enter a loop leading to a denial of service. This bug can be only triggered with Apache HTTP Server version 2.4.37 when using OpenSSL version 1.1.1 or later, due to an interaction in changes to handling of renegotiation attempts.