Client: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-34298 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Client from Pulse Secure, with a CVSS 3.0 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. Affected Client versions: 9.1r15. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.97% 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 Pulse Secure Desktop Client to 9.1 or a later version.
- Read the advisory on forums.ivanti.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Pulse Secure | Client | 9.1r15 | Not stated |
| Pulsesecure | client | 9.1r15 and earlier | Not stated |
| Ivanti | Pulse Secure Desktop Client | before 9.1; 9.1 | 9.1 |
| Ivanti | Pulse Secure Installer Service | 9.1; 22.4.1439 | Not stated |
| Ivanti | Secure Access Client | 22.2; 22.3 | 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
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (trendmicro.com).
Official description
Pulse Secure Client SetupService Directory Traversal Local Privilege Escalation Vulnerability. This vulnerability allows local attackers to escalate privileges on affected installations of Pulse Secure Client. An attacker must first obtain the ability to execute low-privileged code on the target system in order to exploit this vulnerability. The specific flaw exists within SetupService. The issue results from the lack of proper validation of a user-supplied path prior to using it in file operations. An attacker can leverage this vulnerability to escalate privileges and execute arbitrary code in the context of the service. Was ZDI-CAN-17687.
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: total).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- zerodayinitiative.com/advisories/ZDI-23-858/Third Party Advisory
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 8.8 High severity
- 8.8 High severity
- 8.8 High severity
- 7.8 High severity
- 8.8 High severity
- 7.2 High severity
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