use-after-free issue leads to denial of service

Summary

NGINX Open Source has a vulnerability in the ngx_http_v3_module module. When NGINX Open Source is configured to use the HTTP/3 QUIC module, a remote unauthenticated attacker along with conditions beyond their control can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream. This may cause a Use-after-Free in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. A flaw was found in the ngx_http_v3_module module of NGINX. When NGINX is configured to use the HTTP/3 QUIC module, an attacker can use a specially crafted HTTP/3 session to reopen a QPACK encoder stream and cause a use-after-free issue, potentially allowing code execution or a denial of service by forcing the process to restart. This vulnerability is only exploitable when NGINX is configured to use the HTTP/3 QUIC module. This issue allows a remote unauthenticated attacker to potentially execute arbitrary code or cause a denial of service by forcing the worker process to restart. Default Red Hat Enterprise Linux security features, including SELinux enforcement, Address Space Layout Randomization (ASLR) and NX (No-Execute) stack protection, significantly increase the difficulty of achieving arbitrary code execution, limiting the impact of this vulnerability. Due to these reasons, this vulnerability has been rated with an important severity. Red Hat severity: Important — CVSS 8.1 (CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H). Weakness: CWE-416. No fixing RHSA erratum has published yet; monitor the Red Hat CVE page and patch when it ships.