Sun(TM) ONE / iPlanet Web Server 4.1 and 6.0 Remote Buffer Overflow
Release Date: August 8, 2002
Severity:
High (Remote SYSTEM/ROOT)
Systems Affected:
iPlanet 6.0 and prior
Description:
A vulnerability in transfer chunking can be exploited to remotely execute
code of an attacker's choice on a vulnerable machine. By sending a carefully
crafted session, an attacker can overwrite a section of the heap. Various
data structures in the overwritten heap can be manipulated to move attacker
supplied data to attacker supplied memory addresses, thereby altering the
flow of execution into an attacker supplied payload.
Note this variant is not the integer overflow affecting IIS and Apache that
was discovered during regression testing with Microsoft. This is another
variant relating to incorrect size calculation.
The following example will show the vulnerable condition:
**************Begin Session****************
POST /EEYE.html HTTP/1.1
Host: www.EEYE2002.com
Transfer-Encoding: chunked
Content-Length: 22
4
EEYE
7FFFFFFF
[DATA]
**************End Session******************
[DATA] will overwrite heap memory. Increase or decrease depending on
implementation.
Technical Description:
The example session above overwrites a section of the heap that contains
data structures related to the Memory management system. By manipulating the
content of these structures, we can overwrite an arbitrary 4 bytes of memory
with an attacker supplied address.
It is widely assumed that the risk for these type of vulnerabilities is
fairly low due to the fact that addressing is dynamic and that you must use
brute force in your attack; however, this is false assumption and
exploitation can be successful with one attempt, across dll versions. An
attacker can overwrite static global variables, stored function pointers,
process management structures, memory management structures, or any number
of data types that will allow him to gain control of the target application
in one session.
Vendor Status:
Sun has released a security bulletin and patch:
http://www.sun.com/service/support/software/iplanet/alerts/transferencodinga
lert-23july2002.html
Credit: Riley Hassell
Greetings:
Eli, Kasia, Halvar, FX, and the three amigos K2, Dark Spyrit, and Joey.
Copyright (c) 1998-2002 eEye Digital Security
Permission is hereby granted for the redistribution of this alert
electronically. It is not to be edited in any way without express consent of
eEye. If you wish to reprint the whole or any part of this alert in any
other medium excluding electronic medium, please e-mail alert@eEye.com for
permission.
Disclaimer
The information within this paper may change without notice. Use of this
information constitutes acceptance for use in an AS IS condition. There are
NO warranties with regard to this information. In no event shall the author
be liable for any damages whatsoever arising out of or in connection with
the use or spread of this information. Any use of this information is at the
user's own risk.
Feedback
Please send suggestions, updates, and comments to:
eEye Digital Security
http://www.eEye.com
info@eEye.com
Release Date: August 8, 2002
Severity:
High (Remote SYSTEM/ROOT)
Systems Affected:
iPlanet 6.0 and prior
Description:
A vulnerability in transfer chunking can be exploited to remotely execute
code of an attacker's choice on a vulnerable machine. By sending a carefully
crafted session, an attacker can overwrite a section of the heap. Various
data structures in the overwritten heap can be manipulated to move attacker
supplied data to attacker supplied memory addresses, thereby altering the
flow of execution into an attacker supplied payload.
Note this variant is not the integer overflow affecting IIS and Apache that
was discovered during regression testing with Microsoft. This is another
variant relating to incorrect size calculation.
The following example will show the vulnerable condition:
**************Begin Session****************
POST /EEYE.html HTTP/1.1
Host: www.EEYE2002.com
Transfer-Encoding: chunked
Content-Length: 22
4
EEYE
7FFFFFFF
[DATA]
**************End Session******************
[DATA] will overwrite heap memory. Increase or decrease depending on
implementation.
Technical Description:
The example session above overwrites a section of the heap that contains
data structures related to the Memory management system. By manipulating the
content of these structures, we can overwrite an arbitrary 4 bytes of memory
with an attacker supplied address.
It is widely assumed that the risk for these type of vulnerabilities is
fairly low due to the fact that addressing is dynamic and that you must use
brute force in your attack; however, this is false assumption and
exploitation can be successful with one attempt, across dll versions. An
attacker can overwrite static global variables, stored function pointers,
process management structures, memory management structures, or any number
of data types that will allow him to gain control of the target application
in one session.
Vendor Status:
Sun has released a security bulletin and patch:
http://www.sun.com/service/support/software/iplanet/alerts/transferencodinga
lert-23july2002.html
Credit: Riley Hassell
Greetings:
Eli, Kasia, Halvar, FX, and the three amigos K2, Dark Spyrit, and Joey.
Copyright (c) 1998-2002 eEye Digital Security
Permission is hereby granted for the redistribution of this alert
electronically. It is not to be edited in any way without express consent of
eEye. If you wish to reprint the whole or any part of this alert in any
other medium excluding electronic medium, please e-mail alert@eEye.com for
permission.
Disclaimer
The information within this paper may change without notice. Use of this
information constitutes acceptance for use in an AS IS condition. There are
NO warranties with regard to this information. In no event shall the author
be liable for any damages whatsoever arising out of or in connection with
the use or spread of this information. Any use of this information is at the
user's own risk.
Feedback
Please send suggestions, updates, and comments to:
eEye Digital Security
http://www.eEye.com
info@eEye.com