Symantec Encryption Management Server Remote Command Injection

`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  
`