An issue was discovered in GNOME GLib before 2.66.8. When g_file_replace() is used with G_FILE_CREATE_REPLACE_DESTINATION to replace a path that is a dangling symlink, it incorrectly also creates the target of the symlink as an empty file, which could conceivably have security relevance if the symlink is attacker-controlled. (If the path is a symlink to a file that already exists, then the contents of that file correctly remain unchanged.)
CWE-59
CVE-2021-28163
In Eclipse Jetty 9.4.32 to 9.4.38, 10.0.0.beta2 to 10.0.1, and 11.0.0.beta2 to 11.0.1, if a user uses a webapps directory that is a symlink, the contents of the webapps directory is deployed as a static webapp, inadvertently serving the webapps themselves and anything else that might be in that directory.
CVE-2021-28098
An issue was discovered in Forescout CounterACT before 8.1.4. A local privilege escalation vulnerability is present in the logging function. SecureConnector runs with administrative privileges and writes logs entries to a file in %PROGRAMDATA%ForeScout SecureConnector that has full permissions for the Everyone group. Using a symbolic link allows an attacker to point the log file to a privileged location such as %WINDIR%System32. The resulting log file adopts the file permissions of the source of the symbolic link (in this case, the Everyone group). The log file in System32 can be replaced and renamed with a malicious DLL for DLL hijacking.
CVE-2021-27851
A security vulnerability that can lead to local privilege escalation has been found in ’guix-daemon’. It affects multi-user setups in which ’guix-daemon’ runs locally. The attack consists in having an unprivileged user spawn a build process, for instance with `guix build`, that makes its build directory world-writable. The user then creates a hardlink to a root-owned file such as /etc/shadow in that build directory. If the user passed the –keep-failed option and the build eventually fails, the daemon changes ownership of the whole build tree, including the hardlink, to the user. At that point, the user has write access to the target file. Versions after and including v0.11.0-3298-g2608e40988, and versions prior to v1.2.0-75109-g94f0312546 are vulnerable.
CVE-2021-27229
Mumble before 1.3.4 allows remote code execution if a victim navigates to a crafted URL on a server list and clicks on the Open Webpage text.
CVE-2021-27241
This vulnerability allows local attackers to delete arbitrary directories on affected installations of Avast Premium Security 20.8.2429 (Build 20.8.5653.561). An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within the AvastSvc.exe module. By creating a directory junction, an attacker can abuse the service to delete a directory. An attacker can leverage this vulnerability to create a denial-of-service condition on the system. Was ZDI-CAN-12082.