The eupdatedb utility in esearch creates a file in /tmp without first checking for symlinks. This makes it possible for any user to create arbitrary files.
| Package | Arch | Vulnerable | Unaffected |
|---|---|---|---|
| app-portage/esearch | * | <= 0.6.1 | >= 0.6.2 |
Esearch is a replacement for the Portage command "emerge search". It uses an index to speed up searching of the Portage tree.
The eupdatedb utility uses a temporary file (/tmp/esearchdb.py.tmp) to indicate that the eupdatedb process is running. When run, eupdatedb checks to see if this file exists, but it does not check to see if it is a broken symlink. In the event that the file is a broken symlink, the script will create the file pointed to by the symlink, instead of printing an error and exiting.
An attacker could create a symlink from /tmp/esearchdb.py.tmp to a nonexistent file (such as /etc/nologin), and the file will be created the next time esearchdb is run.
There is no known workaround at this time. All users should upgrade to the latest available version of esearch.
All users should upgrade to the latest available version of esearch, as follows:
# emerge sync # emerge -pv ">=app-portage/esearch-0.6.2" # emerge ">=app-portage/esearch-0.6.2"