dom4j before 2.0.3 and 2.1.x before 2.1.3 allows external DTDs and External Entities by default, which might enable XXE attacks. However, there is popular external documentation from OWASP showing how to enable the safe, non-default behavior in any application that uses dom4j.

OverlayFS in the Linux kernel before 3.0.0-16.28, as used in Ubuntu 10.0.4 LTS and 11.10, is missing inode security checks which could allow attackers to bypass security restrictions and perform unauthorized actions.

In NetworkManager 0.9.2.0, when a new wireless network was created with WPA/WPA2 security in AdHoc mode, it created an open/insecure network.

debian/guest-account in Light Display Manager (lightdm) 1.0.x before 1.0.6 and 1.1.x before 1.1.7, as used in Ubuntu Linux 11.10, allows local users to delete arbitrary files via a space in the name of a file in /tmp. NOTE: this identifier was SPLIT per ADT1/ADT2 due to different codebases and affected versions. CVE-2012-6648 has been assigned for the gdm-guest-session issue.

The default keybindings for wwm in LTSP Display Manager (ldm) 2.2.x before 2.2.7 allow remote attackers to execute arbitrary commands via the KP_RETURN keybinding, which launches a terminal window.

ppa.py in Software Properties before 0.81.13.3 does not validate the server certificate when downloading PPA GPG key fingerprints, which allows man-in-the-middle (MITM) attackers to spoof GPG keys for a package repository.

DistUpgrade/DistUpgradeFetcherCore.py in Update Manager before 1:0.87.31.1, 1:0.134.x before 1:0.134.11.1, 1:0.142.x before 1:0.142.23.1, 1:0.150.x before 1:0.150.5.1, and 1:0.152.x before 1:0.152.25.5 on Ubuntu 8.04 through 11.10 does not verify the GPG signature before extracting an upgrade tarball, which allows man-in-the-middle attackers to (1) create or overwrite arbitrary files via a directory traversal attack using a crafted tar file, or (2) bypass authentication via a crafted meta-release file.

DistUpgrade/DistUpgradeViewKDE.py in Update Manager before 1:0.87.31.1, 1:0.134.x before 1:0.134.11.1, 1:0.142.x before 1:0.142.23.1, 1:0.150.x before 1:0.150.5.1, and 1:0.152.x before 1:0.152.25.5 does not properly create temporary files, which allows local users to obtain the XAUTHORITY file content for a user via a symlink attack on the temporary file.

The Ubuntu AccountsService package before 0.6.14-1git1ubuntu1.1 does not properly drop privileges when changing language settings, which allows local users to modify arbitrary files via unspecified vectors.

Untrusted search path vulnerability in pam_motd (aka the MOTD module) in libpam-modules before 1.1.3-2ubuntu2.1 on Ubuntu 11.10, before 1.1.2-2ubuntu8.4 on Ubuntu 11.04, before 1.1.1-4ubuntu2.4 on Ubuntu 10.10, before 1.1.1-2ubuntu5.4 on Ubuntu 10.04 LTS, and before 0.99.7.1-5ubuntu6.5 on Ubuntu 8.04 LTS, when using certain configurations such as "session optional pam_motd.so", allows local users to gain privileges by modifying the PATH environment variable to reference a malicious command, as demonstrated via uname.