Compaq Tru64 kdebugd Remote Arbitrary File Write Vulnerability
BID:1693
Info
Compaq Tru64 kdebugd Remote Arbitrary File Write Vulnerability
| Bugtraq ID: | 1693 |
| Class: | Access Validation Error |
| CVE: |
CVE-2000-0845 |
| Remote: | Yes |
| Local: | No |
| Published: | Sep 19 2000 12:00AM |
| Updated: | Jul 11 2009 03:56AM |
| Credit: | First made public in Enigma security advisory EN18090001, published on September 19, 2000. |
| Vulnerable: |
Digital (Compaq) TRU64/DIGITAL UNIX 5.0 Digital (Compaq) TRU64/DIGITAL UNIX 4.0 f Digital (Compaq) TRU64/DIGITAL UNIX 4.0 e Digital (Compaq) TRU64/DIGITAL UNIX 4.0 d |
| Not Vulnerable: | |
Discussion
Compaq Tru64 kdebugd Remote Arbitrary File Write Vulnerability
Compaq's Tru64 (formerly known as 'Digital Unix') ships with a daemon that is vulnerable to a serious remote attack. The kdebugd daemon (which is started by inetd), accepts an initiation packet when a client connects to it. This packet contains two strings, "kdebugd" and an optional filename to where the session can be logged on the server running kdebugd. The file that is specified is then written to by kdebugd with root priviliges, with most of what is written being input from the client.
This can lead to a complete remote compromise of the system if appropriate files are written to properly. An example of this is writing to /etc/hosts.equiv, where "+ +" can be appended to the file which would then allow anybody from any host to log into the target system without password authentication (using r-services). Because some extra data is written to the target "log file" (that is not directly from the client..), more "syntax dependent" attacks such as adding an entry to /etc/passwd may not be feasible. Another thing to note is that the file must already exist on the system, so an attacker can't create "/.rhosts" if it doesn't exist.
This vulnerability can also be used to read any file on the filesystem. The attacker can use this vulnerability to write to /etc/remote and enter filenames which they wish to read, such as /etc/passwd. After doing this, they can re-connect to kdebugd and request the new entry that they previously wrote to /etc/remote. This will result in kdebugd opening the file, reading it and sending its contents to the client.
Compaq's Tru64 (formerly known as 'Digital Unix') ships with a daemon that is vulnerable to a serious remote attack. The kdebugd daemon (which is started by inetd), accepts an initiation packet when a client connects to it. This packet contains two strings, "kdebugd" and an optional filename to where the session can be logged on the server running kdebugd. The file that is specified is then written to by kdebugd with root priviliges, with most of what is written being input from the client.
This can lead to a complete remote compromise of the system if appropriate files are written to properly. An example of this is writing to /etc/hosts.equiv, where "+ +" can be appended to the file which would then allow anybody from any host to log into the target system without password authentication (using r-services). Because some extra data is written to the target "log file" (that is not directly from the client..), more "syntax dependent" attacks such as adding an entry to /etc/passwd may not be feasible. Another thing to note is that the file must already exist on the system, so an attacker can't create "/.rhosts" if it doesn't exist.
This vulnerability can also be used to read any file on the filesystem. The attacker can use this vulnerability to write to /etc/remote and enter filenames which they wish to read, such as /etc/passwd. After doing this, they can re-connect to kdebugd and request the new entry that they previously wrote to /etc/remote. This will result in kdebugd opening the file, reading it and sending its contents to the client.
Exploit / POC
Compaq Tru64 kdebugd Remote Arbitrary File Write Vulnerability
Currently the SecurityFocus staff are not aware of any exploits for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].
Currently the SecurityFocus staff are not aware of any exploits for this issue. If you feel we are in error or are aware of more recent information, please mail us at: [email protected].
Solution / Fix
Compaq Tru64 kdebugd Remote Arbitrary File Write Vulnerability
Solution:
Currently the SecurityFocus staff are not aware 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 aware 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].