The (1) ZD_MissingPlayer, (2) ZD_UseItem, and (3) ZD_LoadNewClientLevel functions in sv_main.cpp for (a) Zdaemon 1.08.01 and (b) X-Doom allows remote attackers to cause a denial of service (crash) via an invalid player slot or item number, which causes an invalid memory access, possibly due to an invalid array index.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25593
http://www.vupen.com/english/advisories/2006/1199
http://www.vupen.com/english/advisories/2006/1198
http://www.securityfocus.com/bid/17340
http://www.securityfocus.com/archive/1/429521/100/0/threaded
http://securityreason.com/securityalert/662
http://secunia.com/advisories/19509
http://secunia.com/advisories/19496
http://lists.grok.org.uk/pipermail/full-disclosure/2006-March/044775.html