STIGUI
V-256662CAT II — Medium severitySV-256662r961152_rule

VAMI must protect against or limit the effects of HTTP types of denial-of-service (DoS) attacks.

Rule version VCLD-70-000018 · STIG v1 · 2026-08-31

Discussion

In UNIX and related computer operating systems, a file descriptor is an indicator used to access a file or other input/output resource, such as a pipe or network connection. File descriptors index into a per-process file descriptor table maintained by the kernel, which in turn indexes into a systemwide table of files opened by all processes, called the file table.

As a single-threaded server, Lighttpd must be limited in the number of file descriptors that can be allocated. This will prevent Lighttpd from being used in a form of DoS attack against the operating system.

Check

At the command prompt, run the following command:

# /opt/vmware/sbin/vami-lighttpd -p -f /opt/vmware/etc/lighttpd/lighttpd.conf 2>/dev/null|grep "server.max-fds"|sed 's: ::g'

Expected result:

server.max-fds=2048

If the output does not match the expected result, this is a finding.

Note: The command must be run from a bash shell and not from a shell generated by the "appliance shell". Use the "chsh" command to change the shell for the account to "/bin/bash". Refer to KB Article 2100508 for more details:

https://kb.vmware.com/s/article/2100508

Fix

Navigate to and open:

/opt/vmware/etc/lighttpd/lighttpd.conf

Add or reconfigure the following value:

server.max-fds = 2048

Restart the service with the following command:

# vmon-cli --restart applmgmt

Identifiers

Group ID
V-256662
Group title
SRG-APP-000246-WSR-000149
Rule ID
SV-256662r961152_rule
Check ID
C-60337r888506_chk
Fix ID
F-60280r888507_fix