Junos OS Evolved: Improper Handling of Values
CVE-2024-39531 is a high-severity improper handling of values 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 21.4R3-S7-EVO, 22.1R3-S6-EVO, 22.2R3-S3-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 0.44% 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 21.4R3-S7-EVO or 22.1R3-S6-EVO or 22.2R3-S3-EVO or 22.3R3-S3-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 21.4R3-S7-EVO; 22.1 up to, but not including, 22.1R3-S6-EVO; 22.2 up to, but not including, 22.2R3-S3-EVO; 22.3 up to, but not including, 22.3R3-S3-EVO; 22.4 up to, but not including, 22.4R3-S2-EVO; 23.2 up to, but not including, 23.2R2-EVO; 23.4 up to, but not including, 23.4R1-S1-EVO, 23.4R2-EVO; 23.4 up to, but not including, 23.4R1-S1-EVO; and 1 more ranges | 21.4R3-S7-EVO, 22.1R3-S6-EVO, 22.2R3-S3-EVO, 22.3R3-S3-EVO, 22.4R3-S2-EVO, 23.2R2-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 CNA (juniper.net).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.5 | High | CNA (juniper.net) |
Official description
An Improper Handling of Values vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS Evolved on ACX 7000 Series allows a network-based, unauthenticated attacker to cause a Denial-of-Service (DoS). If a value is configured for DDoS bandwidth or burst parameters for any protocol in a queue, all protocols which share the same queue will have their bandwidth or burst value changed to the new value. If, for example, OSPF was configured with a certain bandwidth value, ISIS would also be limited to this value. So inadvertently either the control plane is open for a high level of specific traffic which was supposed to be limited to a lower value, or the limit for a certain protocol is so low that chances to succeed with a volumetric DoS attack are significantly increased. This issue affects Junos OS Evolved on ACX 7000 Series: * All versions before 21.4R3-S7-EVO, * 22.1 versions before 22.1R3-S6-EVO, * 22.2 versions before 22.2R3-S3-EVO, * 22.3 versions before 22.3R3-S3-EVO, * 22.4 versions before 22.4R3-S2-EVO, * 23.2 versions before 23.2R2-EVO, * 23.4 versions before 23.4R1-S1-EVO, 23.4R2-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Handling of Values
The product does not properly handle when the expected number of values for parameters, fields, or arguments is not provided in input, or if those values are undefined.
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
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
Recent Improper Handling of Values vulnerabilities
- 7.5 High severity
- 7.5 High severity
Spotted an error? Tell us.