Vigil@nce: FreeBSD, NetBSD, OpenBSD, denial of service of ftpd
March 2010 by Vigil@nce
SYNTHESIS OF THE VULNERABILITY
An attacker can use the LIST command, in order to force ftpd to
dereference a NULL pointer, which stops it.
Severity: 2/4
Consequences: denial of service of service
Provenance: internet client
Means of attack: 1 attack
Ability of attacker: technician (2/4)
Confidence: confirmed by the editor (5/5)
Diffusion of the vulnerable configuration: high (3/3)
Creation date: 08/03/2010
IMPACTED PRODUCTS
– FreeBSD
– NetBSD
– OpenBSD
DESCRIPTION OF THE VULNERABILITY
The glob() function is used to obtain the list of files matching a
searched pattern (for example "*.txt").
The ftpd daemon manages the FTP LIST command with glob(). For
example, a ftp client user can run:
ls *.txt
When the used pattern is very complex, the glob() function returns
no entry. However, ftpd does not check this case, and dereferences
a NULL pointer.
An attacker can therefore use the LIST command, in order to force
ftpd to dereference a NULL pointer, which stops it.
CHARACTERISTICS
Identifiers: BID-38559, VIGILANCE-VUL-9501
http://vigilance.fr/vulnerability/FreeBSD-NetBSD-OpenBSD-denial-of-service-of-ftpd-9501