Linux atsar File Manipulation Vulnerability
BID:1048
Info
Linux atsar File Manipulation Vulnerability
| Bugtraq ID: | 1048 |
| Class: | Access Validation Error |
| CVE: | |
| Remote: | No |
| Local: | Yes |
| Published: | Mar 11 2000 12:00AM |
| Updated: | Mar 11 2000 12:00AM |
| Credit: | First posted to Bugtraq by krahmer <[email protected]> on March 11, 2000. |
| Vulnerable: |
AT Computing atsar_linux 1.4 |
| Not Vulnerable: |
AT Computing atsar_linux 1.5 -1.i386 AT Computing atsar_linux 1.5 |
Discussion
Linux atsar File Manipulation Vulnerability
atsar is a linux load monitoring software package released under the GPL by AT Computing. atsadc is a setuid root binary that is included in the atsar package. atsadc is setuid because it obtains informatin via /dev/kmem. atsadc will accept as an argument an output file, which it will open -- without checking to make sure the user executing atsadc has the priviliges to do so. After it has opened and created (or overwritten) the target file as root, the permissions set on the file will allow the attacker to write to it. Since this file is arbitrary, it is possible to gain root locally in any number of ways through creating malicious system files. In Teso's proof of concept exploit, root priviliges are gained by creating a malicious shared library to be preloaded and creating/specifying that library in /etc/ld.so.preload (and then executing a setuid binary..).
Starting with atsar 1.5 the program is no longer suid root as it obtains its information via the /proc file system.
atsar is a linux load monitoring software package released under the GPL by AT Computing. atsadc is a setuid root binary that is included in the atsar package. atsadc is setuid because it obtains informatin via /dev/kmem. atsadc will accept as an argument an output file, which it will open -- without checking to make sure the user executing atsadc has the priviliges to do so. After it has opened and created (or overwritten) the target file as root, the permissions set on the file will allow the attacker to write to it. Since this file is arbitrary, it is possible to gain root locally in any number of ways through creating malicious system files. In Teso's proof of concept exploit, root priviliges are gained by creating a malicious shared library to be preloaded and creating/specifying that library in /etc/ld.so.preload (and then executing a setuid binary..).
Starting with atsar 1.5 the program is no longer suid root as it obtains its information via the /proc file system.
Exploit / POC
Linux atsar File Manipulation Vulnerability
Exploit available:
Exploit available:
Solution / Fix
References
Linux atsar File Manipulation Vulnerability
References:
References:
- Halloween Linux Homepage (in German) (Halloween Linux)
- Teso Security Team Home Page (Teso)