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
.
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
.
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())
https://github.com/hapifhir/org.hl7.fhir.core/blob/b0daf666725fa14476d147522155af1e81922aac/org.hl7.fhir.r4b/src/main/java/org/hl7/fhir/r4b/terminologies/TerminologyCacheManager.java#L99-L105
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.
All org.hl7.fhir.core libraries should be updated to 5.6.106. - https://github.com/hapifhir/org.hl7.fhir.core/pull/1162
Unknown
{ "nvd_published_at": "2023-12-12T17:15:07Z", "cwe_ids": [ "CWE-22" ], "severity": "HIGH", "github_reviewed": true, "github_reviewed_at": "2023-03-10T22:15:55Z" }