a-blog cms: Improper Limitation of a Pathname to a Restricted Directory
CVE-2025-27566 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in a-blog cms from Appleple, with a CVSS 3.1 base score of 7.2 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. Affected a-blog cms versions: prior to Ver. 3.1.43 (Ver. 3.1.x series); prior to Ver. 3.0.47 (Ver. 3.0.x series). The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.49% 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 a-blog cms you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on developer.a-blogcms.jp for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Appleple | a-blog cms | prior to Ver. 3.1.43 (Ver. 3.1.x series); prior to Ver. 3.0.47 (Ver. 3.0.x series) | 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.
- Privileges required
- HighAdministrator-level access is required first.
- 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:H/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 5.1 | Medium | CNA (jpcert.or.jp) |
| CVSS 3.1 | 3.8 | Low | CNA (jpcert.or.jp) |
| CVSS 3.1 | 7.2 | High | NVD |
Official description
Path traversal vulnerability exists in a-blog cms versions prior to Ver. 3.1.43 and versions prior to Ver. 3.0.47. This is an issue with insufficient path validation in the backup feature, and exploitation requires the administrator privilege. If this vulnerability is exploited, a remote authenticated attacker with the administrator privilege may obtain or delete any file on the server.
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: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- jvn.jp/en/vu/JVNVU90760614/Third Party Advisory
Other vulnerabilities in a-blog cms
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 8.1 High severity
- 8.8 High severity
- 9.8 Critical severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 9.8 Critical severity
- 9.1 Critical severity
- 8.8 High severity
- 7.5 High severity
- 8.7 High severity
- 9.4 Critical severity
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