An issue was discovered in Gurux GXDLMS Director through 8.5.1905.1301. When downloading OBIS codes, it does not verify that the downloaded files are actual OBIS codes and doesn't check for path traversal. This allows the attacker exploiting CVE-2020-8809 to send executable files and place them in an autorun directory, or to place DLLs inside the existing GXDLMS Director installation (run on next execution of GXDLMS Director). This can be used to achieve code execution even if the user doesn't have any add-ins installed.
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.
| Link | Tags |
|---|---|
| https://seqred.pl/en/cve-gurux-gxdlms-director/ | third party advisory |
| https://github.com/seqred-s-a/gxdlmsdirector-cve | third party advisory exploit |