CVE-2022-22215 Denial of service in Junos OS

Medium 6.5 Published Updated

A local attacker can cause inode exhaustion and denial of service by repeatedly terminating gRPC connections without cleaning up environment files.

Exploited in the wild
Not known
Login needed
Any signed-in user
Attackable
Over the internet
Victim action needed
Not needed
Fix
None listed

What is CVE-2022-22215?

CVE-2022-22215 is a medium-severity denial of service vulnerability in Juniper Junos, published on 20 Jul 2022. Any signed-in user can exploit it over the network, with no action from the victim.

Official description

A Missing Release of File Descriptor or Handle after Effective Lifetime vulnerability in plugable authentication module (PAM) of Juniper Networks Junos OS and Junos OS Evolved allows a locally authenticated attacker with low privileges to cause a Denial of Service (DoS). It is possible that after the termination of a gRPC connection the respective/var/run/<pid>.env file is not getting deleted which if occurring repeatedly can cause inode exhaustion. Inode exhaustion can present itself in two different ways: 1. The following log message can be observed: host kernel: pid <pid> (<process>), uid <uid> inumber <number> on /.mount/var: out of inodes which by itself is a clear indication. 2. The following log message can be observed: host <process>[<pid>]: ... : No space left on device which is not deterministic and just a representation of a write error which could have several reasons. So the following check needs to be done: user@host> show system storage no-forwarding Filesystem Size Used Avail Capacity Mounted on /dev/ada1p1 475M 300M 137M 69% /.mount/var which indicates that the write error is not actually due to a lack of disk space. If either 1. or 2. has been confirmed, then the output of: user@host> file list /var/run/*.env | count need to be checked and if it indicates a high (>10000) number of files the system has been affected by this issue. This issue affects: Juniper Networks Junos OS All versions prior to 19.1R3-S8; 19.2 versions prior to 19.2R3-S6; 19.3 versions prior to 19.3R3-S5; 19.4 versions prior to 19.4R2-S6, 19.4R3-S7; 20.1 version 20.1R1 and later versions; 20.2 versions prior to 20.2R3-S5; 20.3 versions prior to 20.3R3-S4; 20.4 versions prior to 20.4R3; 21.1 versions prior to 21.1R3; 21.2 versions prior to 21.2R2. Juniper Networks Junos OS Evolved All versions prior to 20.4R3-EVO; 21.1 versions prior to 21.1R3-S1-EVO; 21.2 versions prior to 21.2R1-S1-EVO, 21.2R2-EVO.

Weakness: CWE-772

Which versions are affected by CVE-2022-22215?

It affects 2 products.

Products include Juniper Junos, Juniper Junos Os Evolved.

How do I fix CVE-2022-22215?

No fix has been published for CVE-2022-22215 yet. Limit exposure of the affected software until one is available.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2022-22215 being exploited?

There is no known exploitation of CVE-2022-22215 in the wild and no public exploit code.

All Juniper Junos vulnerabilities

Sources

Also known as GHSA-g948-gw7m-3495.

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