CVE-2021-4115

There is a flaw in polkit which can allow an unprivileged user to cause polkit to crash, due to process file descriptor exhaustion. The highest threat from this vulnerability is to availability. NOTE: Polkit process outage duration is tied to the failing process being reaped and a new one being spawned

Weakness

The product does not properly control the allocation and maintenance of a limited resource.

Affected Software

Name	Vendor	Start Version	End Version
Polkit	Polkit_project	0.117 (including)	0.117 (including)
Red Hat Enterprise Linux 8	RedHat	polkit-0:0.115-13.el8_5.2	*
Policykit-1	Ubuntu	esm-infra/focal	*
Policykit-1	Ubuntu	focal	*
Policykit-1	Ubuntu	impish	*

Potential Mitigations

Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.

NVD	https://nvd.nist.gov/vuln/detail/CVE-2021-4115
CWE	https://cwe.mitre.org/data/definitions/400.html

Uncontrolled Resource Consumption

Weakness

Affected Software

Potential Mitigations

References

CVE-2021-4115

Uncontrolled Resource Consumption

Weakness

Affected Software

Potential Mitigations

Related Attack Patterns

References