FatFs R0.16 and earlier contains a stack overflow bug in f_getlabel() because exFAT label length (XDIR_NumLabel) is trusted without enforcing spec maximums. Thi…

FatFs R0.16 and earlier versions contain a stack-based buffer overflow vulnerability in the f_getlabel() function. The flaw arises because the exFAT label length field (XDIR_NumLabel) is trusted without enforcing the specification's maximum limits, allowing an attacker to trigger a stack overflow. This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow). The CVSS v3.1 score is 7.6 (High), with physical access required (AV:P) but no privileges or user interaction needed. The scope is changed with high impact across confidentiality, integrity, and availability. A proof-of-concept exploit exists, and CISA SSVC rates the technical impact as Total. Affected systems include any embedded or application using FatFs for exFAT filesystem support.