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.
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 1.7.1-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.