Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.

Security Management

// // //
7/25/2019
09:25 AM
Larry Loeb
Larry Loeb
Larry Loeb

Comodo Leaves AV Vulnerabilities Unpatched

Even though Comodo was notified by Tenable in April of the problems, no patches by have been forthcoming from the antivirus firm.

Multiple zero-day vulnerabilities were found in version 12.0.0.6810 of Comodo Antivirus by security firm Tenable. Even though Comodo was notified by Tenable in April of the problems, no patches have been forthcoming from the antivirus firm.

The most pressing of them is CVE-2019-3969, which allows an attacker with access to the targeted system to escape the Comodo Antivirus sandbox (which Comodo refers to as "containment") and escalate privileges to SYSTEM. It has a CVSS score of 6.8 (classified as "medium" or "low" severity) because the vulnerabilities need access to the target system in order to affect it.

David Wells, the researcher who found the problems, described them in much detail in a blog that he wrote on Medium.

But Tenable summarizes the problem this way: "An attacker can bypass this signing check (done for validity—ed.) however by changing the client's process name within its PEB (Process Environment Block), or process hollowing a Comodo/Microsoft signed processes with malicious code. This is because CmdAgent's signature check uses the filename from EnumProcessModules / GetModuleFilename for the COM Client's PID. Once passing trusted binary check, an attacker can obtain an Instance of IServiceProvider. With IServiceProvider, the attacker can then query for an interface to SvcRegKey and perform registry writes through the Out-Of-Proc COM server as "NT AUTHORTIY\SYSTEM", allowing local privilege escalation."

That explanation is composed of fairly dense verbiage, but the problem involves loopbacks within the program structures at a fairly low level.

It has been reported that Comodo says the privilege escalation vulnerability was partly Microsoft's fault, and they may well be looking at the possibility that a PEB name change can occur as a primary cause.

Other problems that Tenable discovered include CVE-2019-3970, an arbitrary file write issue which may allow an attacker to modify virus definitions within the AV. With it, the attacker can create false positives (arbitrary file quarantine) or even allow some malware to bypass signature-based detection.

Three more vulnerabilities reported by Tenable include CVE-2019-3972 (an out-of-bounds read that involves CmdAgent.exe), CVE-2019-3973 (an out-of-bounds write affecting Cmdguard.sys), and 9-3971 (denial of service involving CmdVirth.exe).

CVE-2019-3973 only affects versions of the Comodo AV up to 11.0.0.6582.

The last three CVEs can cause individual application components as well as the kernel to crash.

Wells has posted a proof-of-concept (PoC) exploit code along with a video that shows the exploit in action.

— Larry Loeb has written for many of the last century's major "dead tree" computer magazines, having been, among other things, a consulting editor for BYTE magazine and senior editor for the launch of WebWeek.

Comment  | 
Print  | 
More Insights
Comments
Newest First  |  Oldest First  |  Threaded View
Edge-DRsplash-10-edge-articles
I Smell a RAT! New Cybersecurity Threats for the Crypto Industry
David Trepp, Partner, IT Assurance with accounting and advisory firm BPM LLP,  7/9/2021
News
Attacks on Kaseya Servers Led to Ransomware in Less Than 2 Hours
Robert Lemos, Contributing Writer,  7/7/2021
Commentary
It's in the Game (but It Shouldn't Be)
Tal Memran, Cybersecurity Expert, CYE,  7/9/2021
Register for Dark Reading Newsletters
White Papers
Video
Cartoon
Current Issue
Incorporating a Prevention Mindset into Threat Detection and Response
Threat detection and response systems, by definition, are reactive because they have to wait for damage to be done before finding the attack. With a prevention-mindset, security teams can proactively anticipate the attacker's next move, rather than reacting to specific threats or trying to detect the latest techniques in real-time. The report covers areas enterprises should focus on: What positive response looks like. Improving security hygiene. Combining preventive actions with red team efforts.
Flash Poll
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
CVE-2022-29248
PUBLISHED: 2022-05-25
Guzzle is a PHP HTTP client. Guzzle prior to versions 6.5.6 and 7.4.3 contains a vulnerability with the cookie middleware. The vulnerability is that it is not checked if the cookie domain equals the domain of the server which sets the cookie via the Set-Cookie header, allowing a malicious server to ...
CVE-2022-29402
PUBLISHED: 2022-05-25
TP-Link TL-WR840N EU v6.20 was discovered to contain insecure protections for its UART console. This vulnerability allows attackers to connect to the UART port via a serial connection and execute commands as the root user without authentication.
CVE-2021-27783
PUBLISHED: 2022-05-25
User generated PPKG file for Bulk Enroll may have unencrypted sensitive information exposed.
CVE-2021-27779
PUBLISHED: 2022-05-25
VersionVault Express exposes sensitive information that an attacker can use to impersonate the server or eavesdrop on communications with the server.
CVE-2021-44719
PUBLISHED: 2022-05-25
Docker Desktop 4.3.0 has Incorrect Access Control.