Junos OS Evolved: NULL Pointer Dereference
CVE-2024-21602 is a high-severity NULL pointer dereference 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-S6-EVO, 22.1R3-S5-EVO, 22.2R2-S1-EVO, 22.2R3-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 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 21.4R3-S6-EVO or 22.1R3-S5-EVO or 22.2R2-S1-EVO, 22.2R3-EVO or 22.3R2-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 | 21.4-EVO up to, but not including, 21.4R3-S6-EVO; 22.1-EVO up to, but not including, 22.1R3-S5-EVO; 22.2-EVO up to, but not including, 22.2R2-S1-EVO, 22.2R3-EVO; 22.3-EVO up to, but not including, 22.3R2-EVO | 21.4R3-S6-EVO, 22.1R3-S5-EVO, 22.2R2-S1-EVO, 22.2R3-EVO, 22.3R2-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
A NULL Pointer Dereference vulnerability in Juniper Networks Junos OS Evolved on ACX7024, ACX7100-32C and ACX7100-48L allows an unauthenticated, network-based attacker to cause a Denial of Service (DoS). If a specific IPv4 UDP packet is received and sent to the Routing Engine (RE) packetio crashes and restarts which causes a momentary traffic interruption. Continued receipt of such packets will lead to a sustained DoS. This issue does not happen with IPv6 packets. This issue affects Juniper Networks Junos OS Evolved on ACX7024, ACX7100-32C and ACX7100-48L: * 21.4-EVO versions earlier than 21.4R3-S6-EVO; * 22.1-EVO versions earlier than 22.1R3-S5-EVO; * 22.2-EVO versions earlier than 22.2R2-S1-EVO, 22.2R3-EVO; * 22.3-EVO versions earlier than 22.3R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions earlier than 21.4R1-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: NULL Pointer Dereference
The product dereferences a pointer that it expects to be valid but is NULL.
How developers prevent this class of flaw
- For any pointers that could have been modified or provided from a function that can return NULL, check the pointer for NULL before use. When working with a multithreaded or otherwise asynchronous environment, ensure that proper locking APIs are used to lock before the check, and unlock when it has finished.
- Select a programming language that is not susceptible to these issues.
- Check the results of all functions that return a value and verify that the value is non-null before acting upon it.
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
Recent NULL Pointer Dereference vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
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