Hl7 Fhir Core: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-28465 is a high-severity improper limitation of a pathname to a restricted directory vulnerability in Hl7 Fhir Core from Hapifhir, 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 5.6.106 as the first without the flaw, so updating Hl7 Fhir Core to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 1.3% chance of exploitation within 30 days, higher than 71% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Hl7 Fhir Core to 5.6.106 or a later version.
- Read the advisory on 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
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Hapifhir | Hl7 Fhir Core | before 5.6.106 | 5.6.106 |
Version data comes from NVD's product matching. 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
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 7.5 | High | CISA (ADP) |
Official description
The package-decompression feature in HL7 (Health Level 7) FHIR Core Libraries before 5.6.106 allows attackers to copy arbitrary files to certain directories via directory traversal, if an allowed directory name is a substring of the directory name chosen by the attacker. NOTE: this issue exists because of an incomplete fix for CVE-2023-24057.
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: poc, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- github.com/advisories/GHSA-9654-pr4f-gh6mThird Party Advisory
Other references
- smilecdr.com/our-blogNot Applicable
Other vulnerabilities in Hl7 Fhir Core
- 9.1 Critical severity
- 7.5 High severity
- 9.3 Critical severity
- 9.1 Critical severity
- 8.6 High severity
- 8.1 High severity
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 8.8 High severity
- 7.2 High severity
- 8.3 High severity
- 7.5 High severity
- 7.5 High severity
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