E1200 Firmware: Stack-based Buffer Overflow
CVE-2025-60691 is a high-severity stack-based buffer overflow vulnerability in E1200 Firmware from Linksys, 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 E1200 Firmware versions: 2.0.11.001. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.76% chance of exploitation within 30 days, higher than 56% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of E1200 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 |
|---|---|---|---|
| Linksys | E1200 Firmware | 2.0.11.001 | 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
- 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
A stack-based buffer overflow exists in the httpd binary of Linksys E1200 v2 routers (Firmware E1200_v2.0.11.001_us.tar.gz). The apply_cgi and block_cgi functions copy user-supplied input from the "url" CGI parameter into stack buffers (v36, v29) using sprintf without bounds checking. Because these buffers are allocated as single-byte variables, any non-empty input will trigger a buffer overflow. Remote attackers can exploit this vulnerability via crafted HTTP requests to execute arbitrary code or cause denial of service without authentication.
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)
- github.com/yifan20020708/SGTaint-0-day/blob/main/Linksys/Linksys-E1200/CVE-2025-60691.mdExploit, Third Party Advisory
Other references
- linksys.com/Product
Other vulnerabilities in E1200 Firmware
- 7.5 High severity
- 8.4 High severity
- 8.8 High severity
Recent Stack-based Buffer Overflow vulnerabilities
- 8.8 High severity
- 8.4 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
- 7.5 High severity
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