Symantec Encryption Management Server Remote Command Injection

[Aerosol]

Vantage Point Security Advisory 2014-007
========================================

Title: Symantec Encryption Management Server - Remote Command Injection
ID: VP-2014-007
Vendor: Symantec
Affected Product: Symantec Encryption Gateway
Affected Versions: < 3.2.0 MP6
Product Website: http://www.symantec.com/en/sg/gateway-email-encryption/
Author: Paul Craig <paul[at]vantagepoint[dot]sg


Summary:
---------
Symantec Gateway Email Encryption provides centrally managed email encryption
to secure email communications with customers and partners regardless of whether
or not recipients have their own email encryption software.
With Gateway Email Encryption, organizations can minimize the risk of
a data breach while complying with regulatory mandates for information
security and privacy.

Details:
---------
Remote Command Injection vulnerabilities occur when user supplied
input is used directly as a command line argument to a fork(), execv()
or a CreateProcessA() function.

It was found that the binary /usr/bin/pgpsysconf calls the binary
/usr/bin/pgpbackup with unfiltered user supplied input when restoring
a Database Backup from the Symantec Encryption Management Web
Interface .
The user supplied 'filename' value is used directly as a command
argument, and can be concatenated to include additional commands with
the use of the pipe character.
This can allow a lower privileged Administrator to compromise the
Encryption Management Server.

This is demonstrated below in a snippet from pgpsysconf;

.text:08058FEA                 mov     dword ptr [ebx], offset
aUsrBinPgpbacku ; "/usr/bin/pgpbackup"
.text:08058FF0                 cmp     [ebp+var_1D], 0
.text:08058FF4                 jnz     short loc_8059049
.text:08058FF6                 mov     ecx, 4
.text:08058FFB                 mov     edx, 8
.text:08059000                 mov     eax, 0Ch
.text:08059005                 mov     dword ptr [ebx+ecx], offset unk_807AE50
.text:0805900C                 mov     [ebx+edx], esi
.text:0805900F                 mov     dword ptr [ebx+eax], 0
.text:08059016                 call    _fork           ;  Bingo..

An example to exploit this vulnerability and run the ping command can
be seen below.

POST /omc/uploadBackup.event ....
....

Content-Disposition: form-data; name="file";
filename="test123|`ping`|-whatever.tar.gz.pgp"

This vulnerability can be further exploited to gain local root access
by calling the setuid binary pgpsysconf to install a local package
file.


Fix Information:
---------
Upgrade to Symantec Encryption Management Server 3.3.2 MP7.
See http://www.symantec.com/security_response/securityupdates/detail.jsp?fid=security_advisory&pvid=security_advisory&year=&suid=20150129_00
for more information



Timeline:
---------

2014/11/26: Issue Reported.
2015/01/30: Patch Released.


About Vantage Point Security:
---------

Vantage Point Security is the leading provider for penetration testing
and security advisory services in Singapore. Clients in the Financial,
Banking and Telecommunications industries  select Vantage Point
Security based on technical competency and a proven track record to
deliver significant and measurable improvements in their security
posture.

Web: https://www.vantagepoint.sg/
Contact: office[at]vantagepoint[dot]sg

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