Applio: Improper Limitation of a Pathname to a Restricted Directory
CVE-2025-27787 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Applio from IAHispano, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Applio versions: <= 3.2.8-bugfix. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.8% chance of exploitation within 30 days, higher than 57% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Applio you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on securitylab.github.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
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
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.8 | High | CNA (github.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
Applio is a voice conversion tool. Versions 3.2.8-bugfix and prior are vulnerable to denial of service (DoS) in restart.py. `model_name` in train.py takes user input, and passes it to the `stop_train` function in restart.py, which uses it construct a path to a folder with `config.json`. That `config.json` is opened and the list of values under "process_pids" are read. Next all the process IDs listed in the JSON are killed. Using one of the arbitrary file writes, one can write to `logs/foobar` a `config.json` file, which contains a list of process IDs. Then one can access this endpoint to kill these processes. Since an attacker can't know what process is running on which process ID, they can send a list of hundreds of process IDs, which can kill the process that applio is using to run, as well as other, potentially important processes, which leads to DoS. Note that constructing a path with user input also enables path traversal. For example, by supplying "../../" in `model_name` one can access `config.json` freom locations two folders down on the server. As of time of publication, no known patches are available.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- 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.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other references
Other vulnerabilities in Applio
- 9.1 Critical severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 8.8 High severity
- 7.5 High severity
- 7.3 High severity
- 9.8 Critical severity
- 7.5 High severity
- 8.1 High severity
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