Junos OS: Unrestricted Upload of File with Dangerous Type
CVE-2023-28962 is a critical-severity unrestricted upload of file with dangerous type vulnerability in Junos OS from Juniper Networks, with a CVSS 3.1 base score of 9.8 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 19.4R3-S11, 20.1*, 20.2R3-S7 as the first without the flaw, so updating Junos OS to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Junos OS to 19.4R3-S11 or 20.1* or 20.2R3-S7 or 20.3*, whichever matches your release line, or a later version.
- Update Junos to 19.4 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 | before 19.4R3-S11; 20.1R1 up to, but not including, 20.1*; 20.2 up to, but not including, 20.2R3-S7; 20.3R1 up to, but not including, 20.3*; 20.4 up to, but not including, 20.4R3-S6; 21.1R1 up to, but not including, 21.1*; 21.2 up to, but not including, 21.2R3-S4; 21.3 up to, but not including, 21.3R3-S3; and 4 more ranges | 19.4R3-S11, 20.1*, 20.2R3-S7, 20.3*, 20.4R3-S6, 21.1* |
| Juniper Networks | Junos | before 19.4; 19.4; 20.1; 20.2; 20.3; 20.4; 21.1; 21.2; and 5 more ranges | 19.4 |
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
- 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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 5.3 | Medium | CNA (juniper.net) |
| CVSS 3.1 | 9.8 | Critical | NVD |
Official description
An Improper Authentication vulnerability in upload-file.php, used by the J-Web component of Juniper Networks Junos OS allows an unauthenticated, network-based attacker to upload arbitrary files to temporary folders on the device. This issue affects Juniper Networks Junos OS: All versions prior to 19.4R3-S11; 20.1 version 20.1R1 and later versions; 20.2 versions prior to 20.2R3-S7; 20.3 version 20.3R1 and later versions; 20.4 versions prior to 20.4R3-S6; 21.1 version 21.1R1 and later versions; 21.2 versions prior to 21.2R3-S4; 21.3 versions prior to 21.3R3-S3; 21.4 versions prior to 21.4R3-S3; 22.1 versions prior to 22.1R3-S1; 22.2 versions prior to 22.2R2-S1, 22.2R3; 22.3 versions prior to 22.3R1-S2, 22.3R2.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Unrestricted Upload of File with Dangerous Type
The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.
How developers prevent this class of flaw
- Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
- When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
- Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.
More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)
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
- supportportal.juniper.net/JSA70587Mitigation
Other vulnerabilities in Junos OS
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 7.5 High severity
Recent Unrestricted Upload of File with Dangerous Type vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.2 High severity
- 7.5 High severity
- 7.2 High severity
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