It was found that the patch for CVE-2021-3592 introduced a regression which prevented ssh connections to the host system. Since there is no imminent solution for the problem, the patch for CVE-2021-3592 has been reverted. Updated qemu packages are now available to correct this issue.
For Debian 8 jessie, these problems have been fixed in version 1:2.1+dfsg-12+deb8u22.
We recommend that you upgrade your qemu packages.
Further information about Extended LTS security advisories can be found at: https://deb.freexian.com/extended-lts/