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.

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.

NULL pointer dereference vulnerability in ZNC before 0.092 caused by traffic stats when there are unauthenticated connections.

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 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.

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.

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 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.

The CBounceDCCMod::OnPrivCTCP function in bouncedcc.cpp in the bouncedcc module in ZNC 0.200 and 0.202 allows remote attackers to cause a denial of service (crash) via a crafted DCC RESUME request.

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.

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."

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.

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.

Directory traversal vulnerability in ZNC before 0.072 allows remote attackers to overwrite arbitrary files via a crafted DCC SEND request.

Multiple CRLF injection vulnerabilities in webadmin in ZNC before 0.066 allow remote authenticated users to modify the znc.conf configuration file and gain privileges via CRLF sequences in the quit message and other vectors.