There is missing input validation of host names displayed in OpenWrt before 19.07.8. The Connection Status page of the luci web-interface allows XSS, which can be used to gain full control over the affected system via ICMP.

A stored cross-site scripting (XSS) vulnerability was discovered in the Web Interface for OpenWRT LuCI version 19.07 which allows attackers to inject arbitrary Javascript in the OpenWRT Hostname via the Hostname Change operation.

applications/luci-app-ddns/luasrc/model/cbi/ddns/detail.lua in the DDNS package for OpenWrt 19.07 allows remote authenticated users to inject arbitrary commands via POST requests.

In OpenWrt 19.07.x before 19.07.7, when IPv6 is used, a routing loop can occur that generates excessive network traffic between an affected device and its upstream ISP's router. This occurs when a link prefix route points to a point-to-point link, a destination IPv6 address belongs to the prefix and is not a local IPv6 address, and a router advertisement is received with at least one global unique IPv6 prefix for which the on-link flag is set. This affects the netifd and odhcp6c packages.

libuci in OpenWrt before 18.06.9 and 19.x before 19.07.5 may encounter a use after free when using malicious package names. This is related to uci_parse_package in file.c and uci_strdup in util.c.

An issue was discovered in OpenWrt 18.06.0 to 18.06.6 and 19.07.0, and LEDE 17.01.0 to 17.01.7. A bug in the fork of the opkg package manager before 2020-01-25 prevents correct parsing of embedded checksums in the signed repository index, allowing a man-in-the-middle attacker to inject arbitrary package payloads (which are installed without verification).

libubox in OpenWrt before 18.06.7 and 19.x before 19.07.1 has a tagged binary data JSON serialization vulnerability that may cause a stack based buffer overflow.

uhttpd in OpenWrt through 18.06.5 and 19.x through 19.07.0-rc2 has an integer signedness error. This leads to out-of-bounds access to a heap buffer and a subsequent crash. It can be triggered with an HTTP POST request to a CGI script, specifying both "Transfer-Encoding: chunked" and a large negative Content-Length value.