CVE-2023-30546: Contiki-NG has off-by-one error in Antelope DBMS

Contiki-NG is an operating system for Internet of Things devices. An off-by-one error can be triggered in the Antelope database management system in the Contiki-NG operating system in versions 4.8 and prior. The problem exists in the Contiki File System (CFS) backend for the storage of data (file os/storage/antelope/storage-cfs.c). In the functions storagegetindex and storageputindex, a buffer for merging two strings is allocated with one byte less than the maximum size of the merged strings, causing subsequent function calls to the cfsopen function to read from memory beyond the buffer size. The vulnerability has been patched in the "develop" branch of Contiki-NG, and is expected to be included in the next release. As a workaround, the problem can be fixed by applying the patch in Contiki-NG pull request #2425.