CVE-2021-47755
BaseFortify
Publication date: 2026-01-15
Last updated on: 2026-01-15
Assigner: VulnCheck
Description
Description
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| softlink | oliver_library_server | to 8.00.008.053 (exc) |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-22 | 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. |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability in Oliver Library Server v5 allows unauthenticated attackers to download arbitrary system files by exploiting a flaw in the FileServlet endpoint. The 'fileName' parameter is not properly sanitized, so attackers can manipulate it to access sensitive files on the server's filesystem without authorization. [2]
How can this vulnerability impact me? :
An attacker exploiting this vulnerability can remotely retrieve sensitive files from the server, potentially exposing confidential information. This can lead to data breaches, loss of privacy, and compromise of system integrity, as attackers gain unauthorized access to files that should be protected. [2]
How can this vulnerability be detected on my network or system? Can you suggest some commands?
You can detect this vulnerability by attempting to access the FileServlet endpoint with crafted URLs that try to download arbitrary files. For example, use a command like: curl "https://<hostaddress>/oliver/FileServlet?source=serverFile&fileName=c:/windows/iis.log" to see if the server returns the contents of the file. If the file is returned without authentication or sanitization, the system is vulnerable. [2]
What immediate steps should I take to mitigate this vulnerability?
Immediate mitigation steps include restricting access to the FileServlet endpoint, implementing input validation and sanitization on the 'fileName' parameter to prevent arbitrary file access, and applying any available patches or updates from the vendor. Additionally, monitor and block suspicious requests attempting to exploit this vulnerability. [2]