Dsl-7740c Firmware: Improper Access Control
CVE-2025-29515 is a critical-severity improper access control vulnerability in Dsl-7740c Firmware 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 Dsl-7740c Firmware versions: 6.tr069.20211230. 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.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of Dsl-7740c Firmware you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on dlink.com for workarounds and exact fixed builds.
- 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 | Dsl-7740c Firmware | 6.tr069.20211230 | 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
- 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
Incorrect access control in the DELT_file.xgi endpoint of D-Link DSL-7740C with firmware DSL7740C.V6.TR069.20211230 allows attackers to modify arbitrary settings within the device's XML database, including the administrator’s password.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Access Control
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
How developers prevent this class of flaw
- Very carefully manage the setting, management, and handling of privileges. Explicitly manage trust zones in the software.
- Compartmentalize the system to have safe areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area. Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
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
Advisories
Technical write-ups (may include proof of concept)
- gist.github.com/stevenyu113228/0bf32385245f71dfe11b0ef77c468392Exploit, Third Party Advisory
Other vulnerabilities in Dsl-7740c Firmware
- 9.8 Critical severity
Recent Improper Access Control vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 7.3 High severity
- 8.1 High severity
- 8.3 High severity
- 8.8 High severity
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