PASvisu: Improper Limitation of a Pathname to a Restricted Directory
CVE-2022-40977 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in PASvisu from Pilz, 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. The record lists version 1.12.0 as the first without the flaw, so updating PASvisu to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.95% chance of exploitation within 30 days, higher than 62% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update PASvisu to 1.12.0 or a later version.
- Update PMI v7xx (266704 + 266707) to 2.2.0 or a later version.
- Update PMI v8xx (266807, 266812, 266815) to 1.6.102 or a later version.
- 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 |
|---|---|---|---|
| PILZ | PASvisu | 1.0.0 up to, but not including, 1.12.0 | 1.12.0 |
| PILZ | PMI v5xx (265507 + 265512) | 1.0.0 through 1.3.58 | Not stated |
| PILZ | PMI v7xx (266704 + 266707) | 1.0.0 up to, but not including, 2.2.0 | 2.2.0 |
| PILZ | PMI v8xx (266807, 266812, 266815) | 1.0.0 up to, but not including, 1.6.102 | 1.6.102 |
| Pilz | Pmi V507 Firmware | 1.3.58 and earlier | Not stated |
| Pilz | Pmi V512 Firmware | 1.3.58 and earlier | Not stated |
| Pilz | Pmi V704e Firmware | before 2.2.0 | 2.2.0 |
| Pilz | Pmi V707e Firmware | before 2.2.0 | 2.2.0 |
| Pilz | Pmi V807 Firmware | before 1.6.102 | 1.6.102 |
| Pilz | Pmi V812 Firmware | before 1.6.102 | 1.6.102 |
| Pilz | Pmi V815 Firmware | before 1.6.102 | 1.6.102 |
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
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | CNA (cert.vde.com) |
| CVSS 3.1 | 7.5 | High | NVD |
Official description
A path traversal vulnerability was discovered in Pilz PASvisu Server before 1.12.0. An unauthenticated remote attacker could use a zipped, malicious configuration file to trigger arbitrary file writes ('zip-slip'). File writes do not affect confidentiality or availability.
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
Patches and release notes
- cert.vde.com/en/advisories/VDE-2022-033/Mitigation, Third Party Advisory
Other vulnerabilities in PASvisu
- 8.1 High severity
- 7.8 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.0 High severity
- 7.5 High severity
- 7.8 High severity
- 9.8 Critical severity
- 8.8 High severity
- 9.8 Critical severity
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