QID 671013

Nginx is a web server and a reverse proxy server for HTTP, SMTP, POP3 and IMAP protocols, with a strong focus on high concurrency, performance and low memory usage. Security Fix(es): A security issue in nginx resolver was identified, which might allow an attacker who is able to forge UDP packets from the DNS server to cause 1-byte memory overwrite, resulting in worker process crash or potential other impact.(CVE-2021-23017) NGINX before 1.13.6 has a buffer overflow for years that exceed four digits, as demonstrated by a file with a modification date in 1969 that causes an integer overflow (or a false modification date far in the future), when encountered by the autoindex module.(CVE-2017-20005) ALPACA is an application layer protocol content confusion attack, exploiting TLS servers implementing different protocols but using compatible certificates, such as multi-domain or wildcard certificates. A MiTM attacker having access to victim's traffic at the TCP/IP layer can redirect traffic from one subdomain to another, resulting in a valid TLS session. This breaks the authentication of TLS and cross-protocol attacks may be possible where the behavior of one protocol service may compromise the other at the application layer.(CVE-2021-3618)
Note: The preceding description block is extracted directly from the security advisory. Using automation, we have attempted to clean and format it as much as possible without introducing additional issues.

An arbitrary attacker may exploit this vulnerability to compromise the system.