N200RE: Stack-based Buffer Overflow
CVE-2024-0998 is a high-severity stack-based buffer overflow vulnerability in N200RE from TOTOLINK, with a CVSS 3.1 base score of 8.8 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected N200RE versions: 9.3.5u.6139_B20201216. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.4% chance of exploitation within 30 days, higher than 73% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of N200RE you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| TOTOLINK | N200RE | 9.3.5u.6139_B20201216 | Not stated |
| TOTOLINK | N200re Firmware | 9.3.5u.6139_b20201216 | 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
- 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:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.2 | High | CNA (vuldb.com) |
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 2.0 | 8.3 | High | CNA (vuldb.com) |
Official description
A vulnerability was found in Totolink N200RE 9.3.5u.6139_B20201216. It has been classified as critical. This affects the function setDiagnosisCfg of the file /cgi-bin/cstecgi.cgi. The manipulation of the argument ip leads to stack-based buffer overflow. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. The associated identifier of this vulnerability is VDB-252267. NOTE: The vendor was contacted early about this disclosure but did not respond in any way.
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
Third-party and government advisories
- vuldb.com/?ctiid.252267Third Party Advisory
- vuldb.com/?id.252267Third Party Advisory
Technical write-ups (may include proof of concept)
- jylsec.notion.site/TOTOLINK-N200RE-has-stack-buffer-overflow-vulnerability-in-setDiagnosisCfg-b2d36451543e4c6…Exploit, Third Party Advisory
Other vulnerabilities in N200RE
- 8.8 High severity
- 7.2 High severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 8.8 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
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