EEYE: McAfee ePolicy Orchestrator Remote Compromise

McAfee ePolicy Orchestrator Remote Compromise

Release Date:
July 13, 2006

Severity:
High (Remote Code Execution)

Vendor:
McAfee

Systems Affected:
McAfee Common Management (EPO) Agent versions below version 3.5.5.438

Overview:
McAfee ePolicy Orchestrator is the remote security management software
for the McAfee enterprise product suite. EPO allows you to configure and
enforce protection policies, deploy and configure agents, and monitor
security status from a centralized console.

eEye Digital Security has discovered a serious flaw within the Framework
Service component of the McAfee EPO management console. The Framework
service is enabled and running by default on all servers and agents. The
framework service listens by default on port 8081 and accepts requests
over the HTTP protocol. The framework service allows for remotely
submitting configuration and update changes. Each request is encrypted,
SHA-1 hashed and DSA signed, and written to a file on disk. Due to a
directory traversal attack, it is possible to write any file with any
contents to anywhere on the remote system.

This flaw allows a remote attacker to anonymously compromise an affected
system and execute code within the SYSTEM context.

Additional Commentary:
This vulnerability was discovered by McAfee and eEye Digital Security,
individually of each other. McAfee had silently fixed this
vulnerability, prior to the discovery by eEye. It is good for any
software company to be proactive in trying to secure their software.
However, it is equally important for software vendors to create a
separation of security and features when providing updates. In this
case, fixing an extremely critical vulnerability without the proper
notification is a disservice to customers. The mindset of most
customers, especially when dealing with agent software, is to use what
works. This creates a scenario where organizations would potentially
choose to stick with their current deployments, rather than re-deploying
hundreds, if not thousands, of new agents for what would appear to
solely contain innocuous feature updates. We hope organizations take
note and verify they do indeed have the latest ePO framework installed,
and if not, update as soon as possible. -Marc Maiffret

Technical Details:
The framework service accepts POST requests over the /spipe/pkg
interface. These POST requests contain a header which indicates the type
of package request, UUID, and computer hostname. Depending on the
request, the block that follows may contain data specific to that
request. In the case of this vulnerability, the type of request
(PackageType) is "PropsResponse". The data that follows first specifies
a directory and xml filename, and is followed by the contents of the xml
file. Due to improper sanity checking on the directory and filename, it
is possible to use a directory traversal attack to write a user defined
filename, with user defined contents, anywhere on the system.
A factor that would hinder exploitation is the fact that the file is
immediately deleted after use - this problem can be overcome by
increasing the file data length field to exceed the actual data length.

Each package request is obfuscated by XOR'ing the package data with the
static byte 0xAA, and is then SHA-1 hashed and DSA signed.

The vulnerable package format follows:

+00h WORD magic = "PO" (0x4F50)
+02h DWORD = 20000001h, 20001001h, or 30000001
+06h DWORD file offset of XML
+0Ah [E0h] fixed-length data
+0Ah DWORD
+0Eh DWORD
+12h DWORD length of XML
+16h [40h] ASCII ??? GUID
+56h [40h] ASCII ??? GUID
+96h DWORD
+9Ah [???] ASCII host name
…

+EAh […] name-value pairs
X+00h DWORD length of following name string
+04h […] ASCII name string (no null terminator)
X+00h DWORD length of following value data
+04h […] value data (null terminated if ASCII string)

X+00h […] XML
+00h WORD
+02h WORD length of following file name string
+04h […] ASCII .xml file name string * traversal attack, may be any
directory and file extension
X+00h DWORD length of following XML * increase length to prevent
deletion
+04h […] ASCII XML * filename data

X+00h DWORD length of signature data = 2Ch
+04h WORD (big-endian) number of bits in DSA signature 'r' component
+06h [14h] DSA signature 'r' component (technically it's
variable-length)
+1Ah WORD (big-endian) number of bits in DSA signature 's' component
+1Ch [14h] DSA signature 's' component (also variable-length)

The package may be modified to generate any file, anywhere on the
system, with any extension.

Exploitation is 100% reliable due to the fact we are merely taking
advantage of functions already implemented within the framework service.

Protection:
Retina - Network Security Scanner - has been updated to identify this
vulnerability.
Blink - Endpoint Vulnerability Prevention - preemptively protects from
this vulnerability.

Vendor Status:
McAfee customers must login to the McAfee customer website and download
version 3.5.5.438 or higher of the Common Management Agent (ePO
Framework) and upgrade existing ePO agent deployments.

For more information, McAfee has published a knowledgebase article,
which can be found here.
https://secure.nai.com/us/forms/downloads/upgrades/login.asp

Credit:
Barnaby Jack
Additional Research: Derek Soeder

Related Links:
Retina Network Security Scanner - Free Trial
Blink Endpoint Vulnerability Prevention - Free Trial

Greetings:
Derek (props!), D R E, Carlos, the Samyo's, MereMac, Big Smooth and the
rest of the boys from R-Block.

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