Summary
HL7 FHIR Partial Path Zip Slip due to bypass of CVE-2023-24057
Why?
To demonstrate this vulnerability, consider "/usr/outnot".startsWith("/usr/out").
The check is bypassed although /outnot is not under the /out directory.
It's important to understand that the terminating slash may be removed when using various String representations of the File object.
For example, on Linux, println(new File("/var")) will print /var, but println(new File("/var", "/") will print /var/;
however, println(new File("/var", "/").getCanonicalPath()) will print /var.
The Fix
Comparing paths with the java.nio.files.Path#startsWith will adequately protect againts this vulnerability.
For example: file.getCanonicalFile().toPath().startsWith(BASE_DIRECTORY) or file.getCanonicalFile().toPath().startsWith(BASE_DIRECTORY_FILE.getCanonicalFile().toPath())
Other Examples
- CVE-2022-31159 - aws/aws-sdk-java
- CVE-2022-23457 - ESAPI/esapi-java-legacy
Vulnerability
While getAbsolutePath will return a normalized path, because the string path is not slash terminated, the guard can be bypassed to write the contents of the Zip file to a sibling directory of the cache directory.
Workarounds
Unknown
References
Impact
Zip Slip protections implemented in CVE-2023-24057 (GHSA-jqh6-9574-5x22) can be bypassed due a partial path traversal vulnerability.
This issue allows a malicious actor to potentially break out of the TerminologyCacheManager cache directory. The impact is limited to sibling directories.
To demonstrate the vulnerability, consider userControlled.getCanonicalPath().startsWith("/usr/out") will allow an attacker to access a directory with a name like /usr/outnot.
Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.
CVE-2023-28465 has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (5.6.106); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
All org.hl7.fhir.core libraries should be updated to 5.6.106.
Frequently Asked Questions
- What is CVE-2023-28465? CVE-2023-28465 is a high-severity path traversal vulnerability in ca.uhn.hapi.fhir:org.hl7.fhir.core (maven), affecting versions < 5.6.106. It is fixed in 5.6.106. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.
- How severe is CVE-2023-28465? CVE-2023-28465 has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which packages are affected by CVE-2023-28465?
ca.uhn.hapi.fhir:org.hl7.fhir.core(maven) (versions < 5.6.106)ca.uhn.hapi.fhir:org.hl7.fhir.convertors(maven) (versions < 5.6.106)ca.uhn.hapi.fhir:org.hl7.fhir.r4b(maven) (versions < 5.6.106)ca.uhn.hapi.fhir:org.hl7.fhir.r5(maven) (versions < 5.6.106)ca.uhn.hapi.fhir:org.hl7.fhir.utilities(maven) (versions < 5.6.106)ca.uhn.hapi.fhir:org.hl7.fhir.validation(maven) (versions < 5.6.106)
- Is there a fix for CVE-2023-28465? Yes. CVE-2023-28465 is fixed in 5.6.106. Upgrade to this version or later.
- Is CVE-2023-28465 exploitable, and should I be worried? Whether CVE-2023-28465 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-28465 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-28465?
- Upgrade
ca.uhn.hapi.fhir:org.hl7.fhir.coreto 5.6.106 or later - Upgrade
ca.uhn.hapi.fhir:org.hl7.fhir.convertorsto 5.6.106 or later - Upgrade
ca.uhn.hapi.fhir:org.hl7.fhir.r4bto 5.6.106 or later - Upgrade
ca.uhn.hapi.fhir:org.hl7.fhir.r5to 5.6.106 or later - Upgrade
ca.uhn.hapi.fhir:org.hl7.fhir.utilitiesto 5.6.106 or later - Upgrade
ca.uhn.hapi.fhir:org.hl7.fhir.validationto 5.6.106 or later
- Upgrade