dir_823x_ax3000_dual_band_gigabit_wirless_router: Improper Control of Generation of Code
CVE-2024-39962 is a critical-severity improper control of generation of code vulnerability in dir_823x_ax3000_dual_band_gigabit_wirless_router 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_823x_ax3000_dual_band_gigabit_wirless_router versions: v21_d240126. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.06% chance of exploitation within 30 days, higher than 82% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of dir_823x_ax3000_dual_band_gigabit_wirless_router you run against the affected versions below, and install the vendor's latest release.
- 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_823x_ax3000_dual_band_gigabit_wirless_router | v21_d240126 | Not stated |
| D-Link | Dir-823x Firmware | 240126 | Not 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
- 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-823X AX3000 Dual-Band Gigabit Wireless Router v21_D240126 was discovered to contain a remote code execution (RCE) vulnerability in the ntp_zone_val parameter at /goform/set_ntp. This vulnerability is exploited via a crafted HTTP request.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
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
Technical write-ups (may include proof of concept)
- gist.github.com/Swind1er/40c33f1b1549028677cb4e2e5ef69109Exploit, Third Party Advisory
Recent Improper Control of Generation of Code vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.3 High severity
- 9.8 Critical severity
- 7.0 High severity
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