Métriques
Métriques |
Score |
Gravité |
CVSS Vecteur |
Source |
V2 |
7.2 |
|
AV:L/AC:L/Au:N/C:C/I:C/A:C |
[email protected] |
EPSS
EPSS est un modèle de notation qui prédit la probabilité qu'une vulnérabilité soit exploitée.
Score EPSS
Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.
Percentile EPSS
Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.
Informations sur l'Exploit
Exploit Database EDB-ID : 19503
Date de publication : 1999-09-16 22h00 +00:00
Auteur : Tymm Twillman
EDB Vérifié : Yes
source: https://www.securityfocus.com/bid/650/info
Lack of user input validation in ProFTPD can lead to a remote root vulnerability.
On systems that support it ProFTPD will attempt to modify the name of the program being executed (argv[0]) to display the command being executed by the logged on user. It does this by using snprintf to copy the input of the user into a buffer.
The call to snprintf is in the 'set_proc_title' function in the main.c source file. It is only compiled in if the define PF_ARGV_TYPE equals the PF_ARGV_WRITABLE define.
ProFTPD passes the user input to snprintf as the format argument string of the function call. This allows remote users to supply possible dangerous format arguments to snprintf.
Tymm Twillman gives the following example:
- ftp to host
- login (anonymous or no)
(this should be all on one line, no spaces)
ftp> ls aaaXXXX%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%u%653300u%n
(replace the X's with the characters with ascii values 0xdc,0x4f,0x07,0x08
consecutively)
Since proftpd will pass on user input data to snprintf, argument attacks are easy. The a's at the beginning are just for alignment, the %u's to skip bytes in the stack, the %653300u is to increment the # of bytes that have been "output", and the %n stores that value (whose LSBs have now flipped over to 0) to the location pointed to by the current "argument" -- which just happens to point right after the a's in this string. The bytes that replace the X's are the address where proftpd keeps the current user ID...
Logging in as an anonymous user, you are still restricted as to some of the things you can do. But with a local login, root compromise at this point is trivial. And it is possible to modify this exploit for other systems, and for remote attacks.
Products Mentioned
Configuraton 0
Gnu>>Glibc >> Version 2.1.1
Références