A path traversal vulnerability exists in A10 Networks AX Loadbalancer versions 2.6.1-GR1-P5, 2.7.0, and earlier. The vulnerability resides in the handling of the filename parameter in the /xml/downloads endpoint, which fails to properly sanitize user input. An unauthenticated attacker can exploit this flaw by sending crafted HTTP requests containing directory traversal sequences to read arbitrary files outside the intended directory. The files returned by the vulnerable endpoint are deleted from the system after retrieval. This can lead to unauthorized disclosure of sensitive information such as SSL certificates and private keys, as well as unintended file deletion.
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.