Junos OS Evolved: Improper Handling of Syntactically Invalid Structure
CVE-2024-21612 is a high-severity improper handling of syntactically invalid structure 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 21.2R3-S7-EVO, 21.3R3-S5-EVO, 21.4R3-S5-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 0.53% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Junos OS Evolved to 21.2R3-S7-EVO or 21.3R3-S5-EVO or 21.4R3-S5-EVO or 22.1R3-S4-EVO, whichever matches your release line, or a later version.
- Read the advisory on supportportal.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 21.2R3-S7-EVO; 21.3 up to, but not including, 21.3R3-S5-EVO; 21.4 up to, but not including, 21.4R3-S5-EVO; 22.1 up to, but not including, 22.1R3-S4-EVO; 22.2 up to, but not including, 22.2R3-S3-EVO; 22.3 up to, but not including, 22.3R3-EVO; 22.4 up to, but not including, 22.4R2-EVO, 22.4R3-EVO | 21.2R3-S7-EVO, 21.3R3-S5-EVO, 21.4R3-S5-EVO, 22.1R3-S4-EVO, 22.2R3-S3-EVO, 22.3R3-EVO |
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 |
Official description
An Improper Handling of Syntactically Invalid Structure vulnerability in Object Flooding Protocol (OFP) service of Juniper Networks Junos OS Evolved allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). On all Junos OS Evolved platforms, when specific TCP packets are received on an open OFP port, the OFP crashes leading to a restart of Routine Engine (RE). Continuous receipt of these specific TCP packets will lead to a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS Evolved * All versions earlier than 21.2R3-S7-EVO; * 21.3 versions earlier than 21.3R3-S5-EVO ; * 21.4 versions earlier than 21.4R3-S5-EVO; * 22.1 versions earlier than 22.1R3-S4-EVO; * 22.2 versions earlier than 22.2R3-S3-EVO ; * 22.3 versions earlier than 22.3R3-EVO; * 22.4 versions earlier than 22.4R2-EVO, 22.4R3-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Syntactically Invalid Structure
The product does not handle or incorrectly handles input that is not syntactically well-formed with respect to the associated specification.
More Improper Handling of Syntactically Invalid Structure vulnerabilities (CWE-228)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Third-party and government 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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