GNU nano before 2.2.4 does not verify whether a file has been changed before it is overwritten in a file-save operation, which allows local user-assisted attackers to overwrite arbitrary files via a symlink attack on an attacker-owned file that is being edited by the victim.

References

• https://nvd.nist.gov/vuln/detail/CVE-2010-1160
• http://drosenbe.blogspot.com/2010/03/nano-as-root.html
• http://lists.gnu.org/archive/html/nano-devel/2010-04/msg00000.html
• http://secunia.com/advisories/39444
• http://svn.savannah.gnu.org/viewvc/trunk/nano/ChangeLog?revision=4503&root=nano&view=markup
• http://www.openwall.com/lists/oss-security/2010/04/14/4
• http://www.securitytracker.com/id?1023891