Junos OS Evolved: Missing Authorization
CVE-2024-39546 is a high-severity missing authorization vulnerability in Junos OS Evolved from Juniper Networks, with a CVSS 3.1 base score of 7.3 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, but only if a user takes part, for example by opening a link or file. The record lists versions 21.2R3-S8-EVO, 21.4R3-S6-EVO, 22.1R3-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 0.18% 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-S8-EVO or 21.4R3-S6-EVO or 22.1R3-S5-EVO or 22.2R3-S3-EVO, whichever matches your release line, or a later version.
- Read the advisory on supportportal.juniper.net for workarounds and exact fixed builds.
- Because the attack needs a user to take part, warn users about unexpected links and files related to this product until it is patched.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Juniper Networks | Junos OS Evolved | before 21.2R3-S8-EVO; 21.4 up to, but not including, 21.4R3-S6-EVO; 22.1 up to, but not including, 22.1R3-S5-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-EVO; 23.2 up to, but not including, 23.2R2-EVO | 21.2R3-S8-EVO, 21.4R3-S6-EVO, 22.1R3-S5-EVO, 22.2R3-S3-EVO, 22.3R3-S3-EVO, 22.4R3-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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- RequiredA user must take an action such as opening a file or link.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H. Scored by CNA (juniper.net).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.0 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.3 | High | CNA (juniper.net) |
| CVSS 3.1 | 7.3 | High | CISA (ADP) |
Official description
A Missing Authorization vulnerability in the Socket Intercept (SI) command file interface of Juniper Networks Junos OS Evolved allows an authenticated, low-privilege local attacker to modify certain files, allowing the attacker to cause any command to execute with root privileges leading to privilege escalation ultimately compromising the system. This issue affects Junos OS Evolved: * All versions prior to 21.2R3-S8-EVO, * 21.4 versions prior to 21.4R3-S6-EVO, * 22.1 versions prior to 22.1R3-S5-EVO, * 22.2 versions prior to 22.2R3-S3-EVO, * 22.3 versions prior to 22.3R3-S3-EVO, * 22.4 versions prior to 22.4R3-EVO, * 23.2 versions prior to 23.2R2-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
How developers prevent this class of flaw
- Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework and the OWASP ESAPI Access Control feature.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- 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 Missing Authorization vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 8.8 High severity
- 7.2 High severity
- 8.2 High severity
- 10.0 Critical severity
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