Software Engineering Institute

Investintech.com's SlimPDF viewer contains multiple vulnerabilities, which include; user mode write access violations, read access violations on block data moves, write addresses being controlled by data from faulting instructions, data from faulting addresses control branch selection, and tainted data is passed to function calls. These vulnerabilities may be exploitable to leverage arbitrary code execution with the privileges of the user running the vulnerable application. If vulnerable code is shared among other Investintech.com products they may also be affected. It has been reported that the following applications are susceptible to a denial of service crash, which may possibly lead to arbitrary code execution: Able2Doc, Able2Doc Professional, Able2Extract, Absolute PDF Server, and Able2Extract Server.

By convincing a user to open an untrusted specially-crafted .PDF file, a remote, unauthenticated attacker may be able to execute arbitrary code with the privileges of the vulnerable application.

Apply an Update

Investintech.com has released the following versions to address these issues in SlimPDF Reader and related products.

Slim PDF Reader v1.0.1.12:
http://www.investintech.com/download/SPR/1.0.1.12/InstallSlimPDFReader.exe

Able2Doc Std 6.0.8.22:
http://www.investintech.com/download/A2E/7.0.8.22/InstallAble2Doc.exe

Able2Doc Pro 6.0.8.22:
http://www.investintech.com/download/A2E/7.0.8.22/InstallAble2DocPro.exe

Able2Extract Std 7.0.8.22:
http://www.investintech.com/download/A2E/7.0.8.22/InstallAble2Extract.exe

Able2Extract Pro 7.0.8.22:
http://www.investintech.com/download/A2E/7.0.8.22/InstallAble2ExtractPro.exe

Workarounds

Use the Microsoft Enhanced Mitigation Experience Toolkit

The Microsoft Enhanced Mitigation Experience Toolkit (EMET) can be used to help prevent exploitation of these vulnerabilities.

Enable DEP in Microsoft Windows

Consider enabling Data Execution Prevention (DEP) in supported versions of Windows. DEP should not be treated as a complete workaround, but it can mitigate the execution of attacker-supplied code in some cases. Microsoft has published detailed technical information about DEP in Security Research & Defense blog posts "Understanding DEP as a mitigation technology" part 1 and part 2. DEP should be used in conjunction with the application of patches or other mitigations described in this document.

Note that when relying on DEP for exploit mitigation, it is important to use a system that supports Address Space Layout Randomization (ASLR) as well. ASLR is not supported by Windows XP or Windows Server 2003 or earlier. ASLR was introduced with Microsoft Windows Vista and Windows Server 2008. Please see the Microsoft SRD blog entry: On the effectiveness of DEP and ASLR for more details.