E5600: Use of a Broken or Risky Cryptographic Algorithm
CVE-2025-9146 is a high-severity use of a broken or risky cryptographic algorithm vulnerability in E5600 from Linksys, with a CVSS 3.1 base score of 8.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected E5600 versions: 1.1.0.26. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.59% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of E5600 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 |
|---|---|---|---|
| Linksys | E5600 | 1.1.0.26 | Not stated |
| Linksys | E5600 Firmware | 1.1.0.26 | 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
- HighSuccess depends on conditions outside the attacker's control.
- 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:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.5 | High | CNA (vuldb.com) |
| CVSS 3.1 | 6.6 | Medium | CNA (vuldb.com) |
| CVSS 3.1 | 8.1 | High | NVD |
| CVSS 2.0 | 6.8 | Medium | CNA (vuldb.com) |
Official description
A flaw has been found in Linksys E5600 1.1.0.26. The affected element is the function verify_gemtek_header of the file checkFw.sh of the component Firmware Handler. Executing manipulation can lead to risky cryptographic algorithm. The attack may be launched remotely. The attack requires a high level of complexity. The exploitability is described as difficult. 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: Use of a Broken or Risky Cryptographic Algorithm
The product uses a broken or risky cryptographic algorithm or protocol.
How developers prevent this class of flaw
- Ensure that the design allows one cryptographic algorithm to be replaced with another in the next generation or version. Where possible, use wrappers to make the interfaces uniform. This will make it easier to upgrade to stronger algorithms. With hardware, design the product at the Intellectual Property (IP) level so that one cryptographic algorithm can be replaced with another in the next generation of the hardware product.
- Carefully manage and protect cryptographic keys (see CWE-320). If the keys can be guessed or stolen, then the strength of the cryptography itself is irrelevant.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Industry-standard implementations will save development time and may be more likely to avoid errors that can occur during implementation of cryptographic algorithms. Consider the ESAPI Encryption feature.
More Use of a Broken or Risky Cryptographic Algorithm vulnerabilities (CWE-327)
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/?id.320525Third Party Advisory, VDB Entry
- vuldb.com/?submit.628642Third Party Advisory, VDB Entry
Technical write-ups (may include proof of concept)
- github.com/IOTRes/IOT_Firmware_Update/blob/main/Linksys/E5600.mdExploit, Third Party Advisory
Other references
- vuldb.com/?ctiid.320525Permissions Required, VDB Entry
- linksys.com/Product
Other vulnerabilities in E5600
- 7.5 High severity
- 10.0 Critical severity
Recent Use of a Broken or Risky Cryptographic Algorithm vulnerabilities
- 7.0 High severity
- 9.9 Critical severity
- 7.5 High severity
- 7.0 High severity
- 7.5 High severity
- 7.6 High severity
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