Junos OS Evolved: Incorrect Permission Assignment for Critical Resource
CVE-2023-28960 is a high-severity incorrect permission assignment for critical resource vulnerability in Junos OS Evolved from Juniper Networks, with a CVSS 3.1 base score of 8.2 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 20.4R3-S5-EVO, 21.2R3-EVO, 21.3R3-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 0.17% 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 20.4R3-S5-EVO or 21.2R3-EVO or 21.3R3-EVO or 21.4R2-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 | 20.4 up to, but not including, 20.4R3-S5-EVO; 21.2 up to, but not including, 21.2R3-EVO; 21.3 up to, but not including, 21.3R3-EVO; 21.4 up to, but not including, 21.4R2-EVO | 20.4R3-S5-EVO, 21.2R3-EVO, 21.3R3-EVO, 21.4R2-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
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- 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:C/C:H/I:H/A:H. Scored by CNA (juniper.net).
Official description
An Incorrect Permission Assignment for Critical Resource vulnerability in Juniper Networks Junos OS Evolved allows a local, authenticated low-privileged attacker to copy potentially malicious files into an existing Docker container on the local system. A follow-on administrator could then inadvertently start the Docker container leading to the malicious files being executed as root. This issue only affects systems with Docker configured and enabled, which is not enabled by default. Systems without Docker started are not vulnerable to this issue. This issue affects Juniper Networks Junos OS Evolved: 20.4 versions prior to 20.4R3-S5-EVO; 21.2 versions prior to 21.2R3-EVO; 21.3 versions prior to 21.3R3-EVO; 21.4 versions prior to 21.4R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved versions prior to 19.2R1-EVO.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Incorrect Permission Assignment for Critical Resource
The product specifies permissions for a security-critical resource in a way that allows that resource to be read or modified by unintended actors.
How developers prevent this class of flaw
- When using a critical resource such as a configuration file, check to see if the resource has insecure permissions (such as being modifiable by any regular user), and generate an error or even exit the software if there is a possibility that the resource could have been modified by an unauthorized party.
- Divide the software into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully defining distinct user groups, privileges, and/or roles. Map these against data, functionality, and the related resources. Then set the permissions accordingly. This will allow you to maintain more fine-grained control over your resources.
- During program startup, explicitly set the default permissions or umask to the most restrictive setting possible. Also set the appropriate permissions during program installation. This will prevent you from inheriting insecure permissions from any user who installs or runs the program.
More Incorrect Permission Assignment for Critical Resource vulnerabilities (CWE-732)
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 Incorrect Permission Assignment for Critical Resource vulnerabilities
- 8.8 High severity
- 7.8 High severity
- 8.1 High severity
- 7.8 High severity
- 7.0 High severity
- 9.8 Critical severity
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