Hi RAQS,
Yes, version 13.1.3.4 is vulnerable.
for a better understanding of security advisory versioning : https://support.f5.com/csp/article/K51812227
"Versions known to be vulnerable: [...] Point releases and hotfixes are not listed in this column, unless a vulnerability is specifically introduced in a given point release or hotfix.
For example, if 13.1.0 is listed as vulnerable, then 13.1.0.1 and 13.1.0.2 are also considered vulnerable if neither of those point releases are listed in the Fixes introduced in column.[...]
Regards