Junos OS Evolved: Improper Update of Reference Count
CVE-2022-22195 is a high-severity improper update of reference count vulnerability in Junos OS Evolved from Juniper Networks, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 20.4R3-S1-EVO, 21.1R3-EVO, 21.2R3-EVO as the first without the flaw, so updating Junos OS Evolved to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.06% chance of exploitation within 30 days, higher than 65% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS Evolved to 20.4R3-S1-EVO or 21.1R3-EVO or 21.2R3-EVO or 21.3R2-EVO, whichever matches your release line, or a later version.
- Read the advisory on kb.juniper.net for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Junos OS Evolved | before 20.4R3-S1-EVO; 21.1 up to, but not including, 21.1R3-EVO; 21.2 up to, but not including, 21.2R3-EVO; 21.3 up to, but not including, 21.3R2-EVO | 20.4R3-S1-EVO, 21.1R3-EVO, 21.2R3-EVO, 21.3R2-EVO |
| Juniper Networks | Junos OS | Not specified in the record | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 2.0 | 7.8 | High | NVD |
Official description
An Improper Update of Reference Count vulnerability in the kernel of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to trigger a counter overflow, eventually causing a Denial of Service (DoS). This issue affects Juniper Networks Junos OS Evolved: All versions prior to 20.4R3-S1-EVO; 21.1 versions prior to 21.1R3-EVO; 21.2 versions prior to 21.2R3-EVO; 21.3 versions prior to 21.3R2-EVO. This issue does not affect Juniper Networks Junos OS.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Update of Reference Count
The product uses a reference count to manage a resource, but it does not update or incorrectly updates the reference count.
More Improper Update of Reference Count vulnerabilities (CWE-911)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Junos OS Evolved
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
- 7.5 High severity
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