CVE-2019-17449: 
Avira Software Updater vulnerability analysis and mitigation

CVE-2019-17449 is a DLL hijacking vulnerability discovered in Avira Antivirus 2019. The vulnerability was disclosed on October 10, 2019, affecting multiple Avira services including Avira ServiceHost, Avira System Speedup, Avira Software Updater, and Avira Optimizer Host processes (SecurityWeek).

The vulnerability allows an attacker to load an arbitrary unsigned DLL into multiple signed processes that run as NT AUTHORITY\SYSTEM. The issue specifically affects the Avira Launcher service, which is installed first. When started, the process attempts to load a missing library from its own directory, allowing attackers to place their own DLL at that location and execute code within Avira.ServiceHost.exe (SecurityWeek).

The vulnerability could potentially lead to defense evasion, persistence, and privilege escalation by loading an arbitrary unsigned DLL into multiple signed processes running with SYSTEM privileges (SecurityWeek).

The vulnerability requires administrator privileges to exploit, as an attacker would need the ability to place a malicious DLL file in specific system locations. Avira has disputed the severity of this vulnerability, stating that since administrator rights are required for exploitation, there is no actual privilege escalation as an administrator could already modify system binaries (SecurityWeek).

Avira addressed the issue on September 18, 2019, though they disputed the classification of the vulnerability. The company maintains that the scenario requires administrator privileges which would already grant an attacker sufficient access to modify system components (SecurityWeek).

The vulnerability was initially reported by SafeBreach Labs security researchers. After disclosure, Avira disputed the CVE classification at MITRE, arguing that the vulnerability would not be useful to attackers since it requires administrator privileges that would already grant extensive system access (SecurityWeek).