Dir-868l Firmware: Improper Neutralization of Special Elements used in an OS Command
CVE-2025-55583 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in Dir-868l Firmware from D-Link, 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. Affected Dir-868l Firmware versions: 2.05b02. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 6.97% chance of exploitation within 30 days, which is in the top 5.77% of all scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Dir-868l Firmware you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on dlink.com 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 |
|---|---|---|---|
| D-Link | Dir-868l Firmware | 2.05b02 | Not stated |
Version data comes from NVD's product matching. 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 CISA (ADP).
Official description
D-Link DIR-868L B1 router firmware version FW2.05WWB02 contains an unauthenticated OS command injection vulnerability in the fileaccess.cgi component. The endpoint /dws/api/UploadFile accepts a pre_api_arg parameter that is passed directly to system-level shell execution functions without sanitization or authentication. Remote attackers can exploit this to execute arbitrary commands as root via crafted HTTP requests.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- dlink.com/en/security-bulletin/Not Applicable
Technical write-ups (may include proof of concept)
- cybermaya.in/posts/Post-44/Exploit, Third Party Advisory
Other references
Other vulnerabilities in Dir-868l Firmware
- 9.8 Critical severity
- 7.3 High severity
- 9.8 Critical severity
D-Link DIR-859 Router Command Execution Exploited
- 9.8 Critical severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 7.3 High severity
- 8.8 High severity
- 8.8 High severity
- 9.1 Critical severity
- 10.0 Critical severity
- 10.0 Critical severity
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