fcrontab in fcron before 3.0.5 allows local users to read arbitrary files via a symlink attack on an unspecified file.

convert-fcrontab in Fcron 2.9.5 and 3.0.0 allows remote attackers to create or overwrite arbitrary files via ".." sequences and a symlink attack on the temporary file that is used during conversion.

The convert-fcrontab program in fcron 3.0.0 might allow local users to gain privileges via a long command-line argument, which causes Linux glibc to report heap memory corruption, possibly because a strcpy in the strdup2 function can "overwrite some data."

fcronsighup in Fcron 2.0.1, 2.9.4, and possibly earlier versions allows local users to gain sensitive information by calling fcronsighup with an arbitrary file, which reveals the contents of the file that can not be parsed in an error message.

fcronsighup in Fcron 2.0.1, 2.9.4, and possibly earlier versions allows local users to delete arbitrary files or create arbitrary empty files via a target filename with a large number of leading slash (/) characters such that fcronsighup does not properly append the intended fcrontab.sig to the resulting string.

Fcron 2.0.1, 2.9.4, and possibly earlier versions leak file descriptors of open files, which allows local users to bypass access restrictions and read fcron.allow and fcron.deny via the EDITOR environment variable.

fcronsighup in Fcron 2.0.1, 2.9.4, and possibly earlier versions allows local users to bypass access restrictions and load an arbitrary configuration file by starting an suid process and pointing the fcronsighup configuration file to a /proc entry that is owned by root but modifiable by the user, such as /proc/self/cmdline or /proc/self/environ.

Thibault Godouet FCron prior to 1.1.1 allows a local user to corrupt another user's crontab file via a symlink attack on the fcrontab temporary file.