package/exim: mark CVE-2022-3620 as ignored

CVE-2022-3620: A vulnerability was found in Exim and classified as
problematic.  This issue affects the function dmarc_dns_lookup of the file
dmarc.c of the component DMARC Handler.  The manipulation leads to use after
free.  The attack may be initiated remotely.  The name of the patch is
12fb3842f81bcbd4a4519d5728f2d7e0e3ca1445.  It is recommended to apply a
patch to fix this issue.  The associated identifier of this vulnerability is
VDB-211919.

This vulnerability is in the DMARC handling, which is only used if
libopendmarc is available AND SUPPORT_DMARC is set to yes, neither of which
is true for Buildroot, so ignore the CVE.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit 43d5ff7ee4c5f012d79ba69ae6c736e3a88d20c7)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/exim/exim.mk

@@ -16,6 +16,9 @@ EXIM_DEPENDENCIES = host-berkeleydb host-pcre2 pcre2 berkeleydb host-pkgconf
 # 0006-Fix-regex-n-use-after-free.-Bug-2915.patch
 EXIM_IGNORE_CVES += CVE-2022-3559
 
+# built without dmarc support
+EXIM_IGNORE_CVES += CVE-2022-3620
+
 # Modify a variable value. It must already exist in the file, either
 # commented or not.
 define exim-config-change # variable-name, variable-value