vigor3900_firmware: Improper Neutralization of Special Elements used in a Command
CVE-2024-43027 is a high-severity improper neutralization of special elements used in a command vulnerability in vigor3900_firmware from DrayTek, with a CVSS 3.1 base score of 8.0 out of 10. It can be exploited from the same local network by an attacker with a low-privileged account, without any action from a user. The record lists version 1.5.1.5_Beta as the first without the flaw, so updating vigor3900_firmware to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.3% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update vigor3900_firmware to 1.5.1.5_Beta or a later version.
- Update vigor2960_firmware to 1.5.1.5_Beta or a later version.
- Update vigor300b_firmware to 1.5.1.5_Beta or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Draytek | vigor3900_firmware | before 1.5.1.5_Beta | 1.5.1.5_Beta |
| Draytek | vigor2960_firmware | before 1.5.1.5_Beta | 1.5.1.5_Beta |
| Draytek | vigor300b_firmware | before 1.5.1.5_Beta | 1.5.1.5_Beta |
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
- LowA basic user account is enough.
- 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:L/UI:N/S:U/C:H/I:H/A:H. Scored by CISA (ADP).
Official description
DrayTek Vigor 3900 before v1.5.1.5_Beta, DrayTek Vigor 2960 before v1.5.1.5_Beta and DrayTek Vigor 300B before v1.5.1.5_Beta were discovered to contain a command injection vulnerability via the action parameter at cgi-bin/mainfunction.cgi.
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 a Command
The product constructs all or part of a command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended command when 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.
- If possible, ensure that all external commands called from the program are statically created.
- Run time: Run time policy enforcement may be used in an allowlist fashion to prevent use of any non-sanctioned commands.
More Improper Neutralization of Special Elements used in a Command vulnerabilities (CWE-77)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Technical write-ups (may include proof of concept)
- github.com/N1nEmAn/wp/blob/main/V3900.mdExploit, Third Party Advisory
Other vulnerabilities in vigor3900_firmware
- 8.0 High severity
- 8.0 High severity
- 8.0 High severity
- 8.0 High severity
- 8.0 High severity
- 8.0 High severity
Recent Improper Neutralization of Special Elements used in a Command vulnerabilities
- 9.8 Critical severity
- 9.8 Critical severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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