[Full-Disclosure] EEYE: Sun(TM) ONE / iPlanet Web Server 4.1 and 6.0 Remote Buffer Overflow
marc at eeye.com
Fri Aug 9 10:12:14 BST 2002
Sun(TM) ONE / iPlanet Web Server 4.1 and 6.0 Remote Buffer Overflow
Release Date: August 8, 2002
High (Remote SYSTEM/ROOT)
iPlanet 6.0 and prior
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:
POST /EEYE.html HTTP/1.1
[DATA] will overwrite heap memory. Increase or decrease depending on
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.
Sun has released a security bulletin and patch:
Credit: Riley Hassell
Eli, Kasia, Halvar, FX, and the three amigos K2, Dark Spyrit, and Joey.
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