znc.cpp in ZNC before 0.092 allows remote authenticated users to cause a denial of service (crash) by requesting traffic statistics when there is an active unauthenticated connection, which triggers a NULL pointer dereference, as demonstrated using (1) a traffic link in the web administration pages or (2) the traffic command in the /znc shell.

Client.cpp in ZNC 0.092 allows remote attackers to cause a denial of service (exception and daemon crash) via a PING command that lacks an argument.

Multiple unspecified vulnerabilities in ZNC 0.092 allow remote attackers to cause a denial of service (exception and daemon crash) via unknown vectors related to "unsafe substr() calls."

ZNC 1.0 allows remote authenticated users to cause a denial of service (NULL pointer reference and crash) via a crafted request to the (1) editnetwork, (2) editchan, (3) addchan, or (4) delchan page in modules/webadmin.cpp.

Stack-based buffer overflow in fish.cpp in the Fish plugin for ZNC, as used in ZNC for Windows (znc-msvc) 0.206 and earlier, allows remote attackers to cause a denial of service (crash) via a long string in a DH1080_INIT message.

The CWebAdminMod::ChanPage function in modules/webadmin.cpp in ZNC before 1.4 allows remote authenticated users to cause a denial of service (NULL pointer dereference and crash) by adding a channel with the same name as an existing channel but without the leading # character, related to a "use-after-delete" error.

ZNC before 1.7.1-rc1 does not properly validate untrusted lines coming from the network, allowing a non-admin user to escalate his privilege and inject rogue values into znc.conf.

ZNC before 1.7.1-rc1 is prone to a path traversal flaw via ../ in a web skin name to access files outside of the intended skins directories.

Modules.cpp in ZNC before 1.7.4-rc1 allows remote authenticated non-admin users to escalate privileges and execute arbitrary code by loading a module with a crafted name.

ZNC before 1.7.3-rc1 allows an existing remote user to cause a Denial of Service (crash) via invalid encoding.

ZNC 1.8.0 up to 1.8.1-rc1 allows authenticated users to trigger an application crash (with a NULL pointer dereference) if echo-message is not enabled and there is no network.

The official znc docker images before 1.7.1-slim contain a blank password for a root user. Systems using the znc docker container deployed by affected versions of the Docker image may allow an remote attacker to achieve root access with a blank password.