CyberSecBulletin
CVE-2022-43645NVD status: Modified

DIR-825: Improper Neutralization of Special Elements used in an OS Command

CVE-2022-43645 is a high-severity improper neutralization of special elements used in an OS command vulnerability in DIR-825 from D-Link, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. Affected DIR-825 versions: 1.0.9. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.95% chance of exploitation within 30 days, higher than 62% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Check which version of DIR-825 you run against the affected versions below, and install the vendor's latest release.
  2. Read the advisory on supportannouncement.us.dlink.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
D-LinkDIR-8251.0.9Not stated
D-LinkDir-825/ee Firmware1.0.9 and earlierNot stated
D-LinkDir-825/ac Firmware1.0.9 and earlierNot stated

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
AdjacentThe attacker must be on the same local network segment.
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:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.8HighNVD
CVSS 3.08.8HighCNA (trendmicro.com)

Official description

This vulnerability allows network-adjacent attackers to execute arbitrary code on affected installations of D-Link DIR-825 1.0.9/EE routers. Authentication is not required to exploit this vulnerability. The specific flaw exists within the IVI plugin for the xupnpd service, which listens on TCP port 4044. The issue results from the lack of proper validation of a user-supplied string before using it to execute a system call. An attacker can leverage this vulnerability to execute code in the context of the admin user. Was ZDI-CAN-19462.

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

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Third-party and government advisories

Other vulnerabilities in DIR-825

All DIR-825 vulnerabilities

Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities

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