3 new CVE's in vim

[Alan Coopersmith <alan.coopersmith () oracle com>]

I haven't seen these make it to the list yet, but three CVE's were
recently assigned for bugs in vim.  [I personally don't see how
there's a security boundary crossed in normal vim usage here, but
could see issues if someone had configured vim to run with raised
privileges for editing system/application configuration files or
similar.]

    -Alan Coopersmith-               alan.coopersmith () oracle com
     Oracle Solaris Engineering - https://blogs.oracle.com/alanc

CVE-2021-3770: vim: Heap-based Buffer Overflow in ex_retab()
Report: https://huntr.dev/bounties/016ad2f2-07c1-4d14-a8ce-6eed10729365/
Fix: patch 8.2.3402: invalid memory access when using :retab with large value
https://github.com/vim/vim/commit/b7081e135a16091c93f6f5f7525a5c58fb7ca9f9

When vim 8.1 or 8.2 is built with --with-features=huge --enable-gui=none
and address sanitizer, a heap-buffer overflow occurs when running:

echo "bGMKc2YICnJldDgwMDAwMDAwMDAwMDAwMDAwMDAw" | base64 -d \
  > fuzz448.txt
vim -u NONE -X -Z -e -s -S fuzz448.txt -c :qa!

-----------------------------------------------------------------------
CVE-2021-3778: vim: Heap-based Buffer Overflow in utf_ptr2char()
Report: https://huntr.dev/bounties/d9c17308-2c99-4f9f-a706-f7f72c24c273/
Fix: patch 8.2.3409: reading beyond end of line with invalid utf-8 character
https://github.com/vim/vim/commit/65b605665997fad54ef39a93199e305af2fe4d7f

When vim 8.2 is built with --with-features=huge --enable-gui=none
and address sanitizer, a heap-buffer overflow occurs when running:

echo "Ywp2XTCqCi4KeQpAMA==" | base64 -d > fuzz000.txt
vim -u NONE -X -Z -e -s -S fuzz000.txt -c :qa!

-----------------------------------------------------------------------

CVE-2021-3796: vim: Use After Free in nv_replace()
Report: https://huntr.dev/bounties/ab60b7f3-6fb1-4ac2-a4fa-4d592e08008d/
Fix: patch 8.2.3428: using freed memory when replacing
https://github.com/vim/vim/commit/35a9a00afcb20897d462a766793ff45534810dc3

When vim 8.2 is built with --with-features=huge --enable-gui=none
and address sanitizer, a use-after-free occurs when running:

LC_ALL=C vim -U NONE -X -Z -e -s -S poc -c :qa!

with the poc file provided in the report.