ONT1GEW GPON: Improper Neutralization of Special Elements used in an OS Command
CVE-2025-34049 is a critical-severity improper neutralization of special elements used in an OS command vulnerability in ONT1GEW GPON from OptiLink, with a CVSS 4.0 base score of 9.4 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected ONT1GEW GPON versions: V2.1.11_X101 Build 1127.190306 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.43% chance of exploitation within 30 days, higher than 85% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of ONT1GEW GPON you run against the affected versions below, and install the vendor's latest release.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| OptiLink | ONT1GEW GPON | V2.1.11_X101 Build 1127.190306 and earlier | 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.
- Attack requirements
- NoneThe attack does not depend on a particular deployment or configuration.
- Privileges required
- HighAdministrator-level access is required first.
- User interaction
- NoneNo action by a victim is required.
- Confidentiality (vulnerable system)
- HighSerious loss of confidentiality on the vulnerable system.
- Integrity (vulnerable system)
- HighSerious loss of integrity on the vulnerable system.
- Availability (vulnerable system)
- HighSerious loss of availability on the vulnerable system.
- Confidentiality (other systems)
- HighSerious loss of confidentiality on systems beyond the vulnerable one.
- Integrity (other systems)
- HighSerious loss of integrity on systems beyond the vulnerable one.
- Availability (other systems)
- HighSerious loss of availability on systems beyond the vulnerable one.
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. Scored by CNA (vulncheck.com).
Official description
An OS command injection vulnerability exists in the OptiLink ONT1GEW GPON router firmware version V2.1.11_X101 Build 1127.190306 and earlier. The router’s web management interface fails to properly sanitize user input in the target_addr parameter of the formTracert and formPing administrative endpoints. An authenticated attacker can inject arbitrary operating system commands, which are executed with root privileges, leading to remote code execution. Successful exploitation enables full compromise of the device. Exploitation evidence was observed by the Shadowserver Foundation on 2025-02-04 UTC.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements used in an OS Command
The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command before it is sent to a downstream component.
How developers prevent this class of flaw
- If at all possible, use library calls rather than external processes to recreate the desired functionality.
- For any data that will be used to generate a command to be executed, keep as much of that data out of external control as possible. For example, in web applications, this may require storing the data locally in the session's state instead of sending it out to the client in a hidden form field.
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
More Improper Neutralization of Special Elements used in an OS Command vulnerabilities (CWE-78)
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
Other references
Recent Improper Neutralization of Special Elements used in an OS Command vulnerabilities
- 9.4 Critical severity
- 9.4 Critical severity
- 8.8 High severity
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
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