CVE-2021-3420

CVE-2021-3420 is a critical integer overflow vulnerability in newlib versions prior to 4.0.0, specifically impacting memory allocation functions like memalign and valloc. This flaw can lead to the allocation of undersized buffers, subsequently resulting in a heap-based buffer overflow. With a CVSS score of 9.8, it presents a severe risk, allowing unauthenticated attackers over a network to achieve high confidentiality, integrity, and availability impacts. Despite its critical severity, there is currently no evidence of active exploitation, public exploit code (Metasploit, Nuclei, ExploitDB), or significant community discussion or media coverage.