A read-after-free vulnerability was discovered in Apache httpd, in modhttp2. A specially crafted http/2 client session could cause the server to read memory that was previously freed during connection shutdown, potentially leading to a crash.

In Apache httpd 2.2.0 to 2.4.29, when generating an HTTP Digest authentication challenge, the nonce sent to prevent reply attacks was not correctly generated using a pseudo-random seed. In a cluster of servers using a common Digest authentication configuration, HTTP requests could be replayed across servers by an attacker without detection.

apache. Multiple issues were addressed by updating to version 2.4.27.