Denial of service in Junos OS and Junos OS Evolved gRPC connection handling

1) Resource exhaustion

EUVDB-ID: #VU65372

Risk: Medium

CVSSv3.1: 6.5 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2022-22215

CWE-ID: CWE-400 - Resource exhaustion

Exploit availability: No

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to failure to release file descriptors (e.g. delete the "respective/var/run/.env" file) in plugable authentication module (PAM) when handling gRPC connection termination events. A remote attacker can trigger inode exhaustion by initiating and terminating a large number of gRPC connections and perform a denial of service (DoS) attack.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Juniper Junos OS: 19.1 - 21.2R1-S2

Junos OS Evolved: 20.4 - 21.3-EVO

External links

http://supportportal.juniper.net/s/article/2022-07-Security-Bulletin-Junos-OS-and-Junos-OS-Evolved-var-run-pid-env-files-are-potentially-not-deleted-during-termination-of-a-gRPC-connection-causing-inode-exhaustion-CVE-2022-22215

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.