Improper Link Resolution Before File Access ('Link Following')
VestaCP through 0.9.8-24 allows attackers to gain privileges by creating symlinks to files for which they lack permissions. After reading the RKEY value from user.conf under the /usr/local/vesta/data/users/admin directory, the admin password can be changed via a /reset/?action=confirm&user=admin&code= URI. This occurs because chmod is used unsafely.
CWE-59 - Improper Link Resolution Before File Access
'Improper link resolution before file access' occurs when software accesses a file resource but fails to verify that the file isn't a link or shortcut to another file. An attacker can potentially gain access to arbitrary files and from there the impact can vary, depending on the application, from sensitive data exposure to remote code execution.