xinetd 2.1.8.x does not properly restrict connections if hostnames are used for access control and the connecting host does not have a reverse DNS entry.

security flaw

Buffer overflow in internal string handling routines of xinetd before 2.1.8.8 allows remote attackers to execute arbitrary commands via a length argument of zero or less, which disables the length check.

security flaw

xinetd 2.1.8 and earlier runs with a default umask of 0, which could allow local users to read or modify files that are created by an application that runs under xinetd but does not set its own safe umask.

security flaw

Multiple vulnerabilities in xinetd 2.3.0 and earlier, and additional variants until 2.3.3, may allow remote attackers to cause a denial of service or execute arbitrary code, primarily via buffer overflows or improper NULL termination.

security flaw

xinetd 2.3.4 leaks file descriptors for the signal pipe to services that are launched by xinetd, which could allow those services to cause a denial of service via the pipe.

security flaw

Memory leak in xinetd 2.3.10 allows remote attackers to cause a denial of service (memory consumption) via a large number of rejected connections.

xinetd: enables unintentional services over tcpmux port

builtins.c in Xinetd before 2.3.15 does not check the service type when the tcpmux-server service is enabled, which exposes all enabled services and allows remote attackers to bypass intended access restrictions via a request to tcpmux port 1.

xinetd: ignores user and group directives for tcpmux services

xinetd does not enforce the user and group configuration directives for TCPMUX services, which causes these services to be run as root and makes it easier for remote attackers to gain privileges by leveraging another vulnerability in a service.