Antivirus software supposedly provide robust security to users against cyber attacks. However, like all other tools, these tools can also suffer security vulnerabilities. Researchers have spotted a serious security vulnerability in Bitdefender Antivirus Free 2020. Upon exploit, this flaw could allow an attacker load unsigned code triggering a privilege escalation.
Bitdefender Antivirus Free 2020 Vulnerability
Researchers from SafeBreach Labs have discovered a security vulnerability in the Bitdefender Antivirus Free 2020 software. Specifically, they spotted a flaw that could result in privilege escalation upon exploiting by a potential attacker.
Explaining their findings in a blog post, the researchers stated that they found a vulnerability exploitable by loading an arbitrary unsigned DLL. The flaw primarily existed owing to a lack of Code Integrity Guard (CIG) mechanism. Thus, it became possible for an attacker to load unsigned codes.
By exploiting the flaw, an attacker could gain SYSTEM access to the device, for which, the researchers stated,
The executable of the service is signed by BitDefender and if the hacker finds a way to execute code within this process, it can be used as an application whitelisting bypass which can lead to security product evasion.
In addition to whitelisting bypass and gaining System privilege, an adversary could also persistently load and execute malicious payloads every time the service loaded.
Explaining the factors contributing to this vulnerability, the researchers stated that the “lack of safe DLL loading due to uncontrolled search patch” and “absence of digital certificate validation” allowed uploading arbitrary DLL.
SafeBreach researchers have explained the technicalities of the flaw in their blog post alongside a PoC.
Bitdefender Patched The Flaw
After finding the vulnerability, the researchers reported it to Bitdefender on July 17, 2019. Bitdefender acknowledged the flaw and eventually patched it on August 14, 2019. They have also published an advisory crediting the SafeBreach Labs researcher.
Regarding the flaw, Bitdefender stated in its advisory,
An Untrusted Search Path vulnerability in the ServiceInstance.dll library versions 18.104.22.168 and lower, as used in Bitdefender Antivirus Free 2020 versions prior to 22.214.171.124, allows an attacker to load an arbitrary DLL file from the search path.
The vulnerability has received the CVE ID CVE-2019-15295 and a CVSS score of 5.9.
Bitdefender rolled-out the fix for the flaw with Bitdefender Antivirus Free version 126.96.36.199. Users of this tool must ensure updating their devices with the latest software version to stay protected.
In the previous month, we heard of several vulnerabilities affecting Comodo Antivirus. These vulnerabilities also included a local privilege escalation flaw for which the researchers demonstrated the proof-of-concept.