dir-823_firmware: Stack-based Buffer Overflow
CVE-2024-27656 is a high-severity stack-based buffer overflow vulnerability in dir-823_firmware 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-823_firmware versions: 1.0.2b05_20181207. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.62% chance of exploitation within 30 days, higher than 50% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of dir-823_firmware you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| D-Link | dir-823_firmware | 1.0.2b05_20181207 | Not stated |
| D-Link | Dir-823g Firmware | 1.0.2b05 | 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
- 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 CISA (ADP).
Official description
D-Link DIR-823G A1V1.0.2B05 was discovered to contain a buffer overflow via the Cookie parameter. This vulnerability allows attackers to cause a Denial of Service (DoS) via a crafted input, and possibly remote code execution.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
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)
- calm-healer-839.notion.site/D-LINK-DIR-823G-OOBW-0x41E2A0-8ea57277c7cd4ea18dbc40bcb41a98f2?pvs=4Exploit, Third Party Advisory
Other vulnerabilities in dir-823_firmware
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
D-Link DIR-859 Router Command Execution Exploited
Recent Stack-based Buffer Overflow vulnerabilities
- 9.0 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 8.0 High severity
- 8.8 High severity
- 8.8 High severity
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