A vulnerability in the PDF parsing module in Clam AntiVirus (ClamAV) Software versions 0.103.0 and 0.103.1 could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper buffer size tracking that may result in a heap buffer over-read. An attacker could exploit this vulnerability by sending a crafted PDF file to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process to crash, resulting in a denial of service condition.
https://blog.clamav.net/2021/04/clamav-01032-security-patch-release.html