Use-After-Free Vulnerability in libvirt Affects Guest Operations
CVE-2021-3975
Key Information:
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What is CVE-2021-3975?
A use-after-free vulnerability exists in the libvirt virtualization API, specifically within the qemuMonitorUnregister() function. This flaw arises when multiple threads call this function without adequate synchronization mechanisms, leading to potential instability. It can be exploited through the virConnectGetAllDomainStats API during the shutdown sequence of a guest virtual machine. An unprivileged attacker with read-only access may leverage this vulnerability to crash the libvirt daemon, resulting in a denial of service. This affects the stability of virtualized environments and requires prompt attention to ensure systems remain operational.
Affected Version(s)
libvirt Fixed in libvirt v7.1.0
Exploit Proof of Concept (PoC)
PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.