D-Link Multiple Routers OS Command Injection
CVE-2018-6530 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in Dir-860l 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-860l Firmware versions: 1.10b04 and earlier. The record does not name a fixed version, so check the vendor advisory. CISA added it to the Known Exploited Vulnerabilities catalogue on September 8, 2022, which means attacks have been observed in the wild, including in ransomware campaigns.
Attackers are already exploiting this vulnerability, according to CISA.
What to do
- Check which version of Dir-860l Firmware you run against the affected versions below, and install the vendor's latest release.
- CISA's required action: The vendor D-Link published an advisory stating the fix under CVE-2018-20114 properly patches KEV entry CVE-2018-6530. If the device is still supported, apply updates per vendor instructions. If the affected device has since entered its end-of-life, it should be disconnected if still in use.
- 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-860l Firmware | 1.10b04 and earlier | Not stated |
| D-Link | Dir-865l Firmware | 1.08b01 and earlier | Not stated |
| D-Link | Dir-868l Firmware | 1.12b04 and earlier | Not stated |
| D-Link | Dir-880l Firmware | 1.08b04 and earlier | 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 NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.8 | Critical | NVD |
| CVSS 3.1 | 9.8 | Critical | CISA (ADP) |
| CVSS 2.0 | 10.0 | High | NVD |
Official description
OS command injection vulnerability in soap.cgi (soapcgi_main in cgibin) in D-Link DIR-880L DIR-880L_REVA_FIRMWARE_PATCH_1.08B04 and previous versions, DIR-868L DIR868LA1_FW112b04 and previous versions, DIR-65L DIR-865L_REVA_FIRMWARE_PATCH_1.08.B01 and previous versions, and DIR-860L DIR860LA1_FW110b04 and previous versions allows remote attackers to execute arbitrary OS commands via the service parameter.
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.
- Added to CISA's Known Exploited Vulnerabilities catalogue.
- Deadline for US federal agencies to remediate, set by CISA.
- CISA published its SSVC assessment (exploitation: active, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2018-6530US Government Resource
Technical write-ups (may include proof of concept)
- github.com/TheBeeMan/Pwning-multiple-dlink-router-via-SOAP-protoExploit, Third Party Advisory
Other vulnerabilities in Dir-860l Firmware
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 7.4 High severity
- 8.8 High severity
Zyxel EMG2926 Routers Command Injection Exploited
- 8.8 High severity
- 9.8 Critical severity
NETGEAR DGN2200 Remote Code Execution Exploited
- 10.0 High severity
GNU Bash OS Command Injection Exploited
- 9.8 Critical severity
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