Symantec Patches DoS Flaw

Wednesday, July 13, 2016 @ 04:07 PM gHale


Symantec patched a denial of service (DoS) vulnerability with its Norton Security’s Portable Executable file scanning functionality.

The issue could end up exploited during the parsing of a special crafted portable executable file, researchers said.

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Because the faulting code is in the IDSvix86 kernel driver, the parsing of the PE file can cause an access violation in the IDSvix86 driver, which would result in denial of service.

The vulnerability ended up tested on version 22.6.0.142 of Symantec Norton Security and on DSvix86 driver version 15.1.0.1263, said Piotr Bania of Cisco Talos, who discovered the issue.

To successfully exploit the vulnerability, an attacker would have to send the victim a crafted file with a large SizeOfRawData field in a section header.

“The parser does not check to make sure that this is within the bounds of the file, or MD5Compress which is the function that causes the segfault, therefore if the parameter is big enough, it can cause the MD5Compress function to access memory which is currently unavailable causing the machine to crash,” Talos researchers said in a blog post.

In an advisory detailing the vulnerability, Symantec said the issue is in the Client Intrusion Detection System (CIDS) driver, which could cause a system crash when interacted with a specially-crafted PE file. The company also said the bug affects not only the Windows version of the Norton Security, but also Symantec Endpoint Protection.

According to Symantec, the security flaw has a CVSS:3.0 base score of 5.0 and is of medium severity because the attacker would have to trick the user to download the malformed PE file and then manipulate it to interact with the vulnerable CIDS engine.