Minicom Capture-file Group Ownership Vulnerability
BID:1599
Info
Minicom Capture-file Group Ownership Vulnerability
| Bugtraq ID: | 1599 |
| Class: | Access Validation Error |
| CVE: | |
| Remote: | No |
| Local: | Yes |
| Published: | Aug 19 2000 12:00AM |
| Updated: | Aug 19 2000 12:00AM |
| Credit: | First posted to Bugtraq by Michal Zalewski <[email protected]> on August 19, 2000. |
| Vulnerable: |
Jukka Lahtinen Minicom 1.83.1 Jukka Lahtinen Minicom 1.83 .0 Jukka Lahtinen Minicom 1.82.1 Jukka Lahtinen Minicom 1.82 .0 |
| Not Vulnerable: |
Mandriva Linux Mandrake 7.1 Jukka Lahtinen Minicom 1.81.1 Debian Linux 2.3 sparc Debian Linux 2.3 powerpc Debian Linux 2.3 alpha Debian Linux 2.3 Debian Linux 2.2 pre potato Debian Linux 2.2 sparc Debian Linux 2.2 powerpc Debian Linux 2.2 arm Debian Linux 2.2 alpha Debian Linux 2.2 Debian Linux 2.1 sparc Debian Linux 2.1 alpha Debian Linux 2.1 68k Debian Linux 2.1 Debian Linux 2.0 r5 Debian Linux 2.0 r2 Debian Linux 2.0 |
Discussion
Minicom Capture-file Group Ownership Vulnerability
Minicom is a unix terminal program often used for communication between computers with modems. It is often installed setgid uucp, as this access is required for regular users to use certain devices on the system. Through specifying a capture-file on the command line, a file can be created with effective gid uucp and thus owned by gid uucp. Where this is a serious concern is on systems using uucp -- critical files writeable by group uucp can be overwritten by exploiting this vulnerability leading to other problems.
Note: One of the versions listed as vulnerable (1.83.1) has been reported as not being vulnerable as a FreeBSD port.
Minicom is a unix terminal program often used for communication between computers with modems. It is often installed setgid uucp, as this access is required for regular users to use certain devices on the system. Through specifying a capture-file on the command line, a file can be created with effective gid uucp and thus owned by gid uucp. Where this is a serious concern is on systems using uucp -- critical files writeable by group uucp can be overwritten by exploiting this vulnerability leading to other problems.
Note: One of the versions listed as vulnerable (1.83.1) has been reported as not being vulnerable as a FreeBSD port.
Exploit / POC
Minicom Capture-file Group Ownership Vulnerability
Taken from Michal Zalewski's original Bugtraq Post:
> @(#)Minicom V1.83.0 (compiled Mar 7 2000)(c) Miquel van Smoorenburg
>
> [lcamtuf@nimue lcamtuf]$ minicom -C foo
> minicom: there is no global configuration file /etc/minirc.dfl
> Ask your sysadm to create one (with minicom -s).
>
> [lcamtuf@nimue lcamtuf]$ ls -l foo
> -rw-rw-r-- 1 lcamtuf uucp 0 Aug 18 12:21 foo
> ^^ ^^^^
>
> Any file can be created anywhere with uucp privledges - it will follow
> symlinks. Not nice on systems running uucp services.
>
Taken from Michal Zalewski's original Bugtraq Post:
> @(#)Minicom V1.83.0 (compiled Mar 7 2000)(c) Miquel van Smoorenburg
>
> [lcamtuf@nimue lcamtuf]$ minicom -C foo
> minicom: there is no global configuration file /etc/minirc.dfl
> Ask your sysadm to create one (with minicom -s).
>
> [lcamtuf@nimue lcamtuf]$ ls -l foo
> -rw-rw-r-- 1 lcamtuf uucp 0 Aug 18 12:21 foo
> ^^ ^^^^
>
> Any file can be created anywhere with uucp privledges - it will follow
> symlinks. Not nice on systems running uucp services.
>
Solution / Fix
Minicom Capture-file Group Ownership Vulnerability
Solution:
Currently the SecurityFocus staff are not ware of any vendor supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].
Solution:
Currently the SecurityFocus staff are not ware of any vendor supplied patches for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].
References
Minicom Capture-file Group Ownership Vulnerability
References:
References:
- Minicom Project Homepage (Jukka Lahtinen)