Re: sendmail and starttls failing
On Sun, Jun 30, 2024 at 23:08:01 +0100, Tim Woodall wrote:
> According to this
> https://support.trustwave.com/kb/KnowledgebaseArticle10016.aspx
>
> bare CRs aren't allowed in emails but this has always worked.
>
> I'm only likely to have cron generating emails like this.
>
> Strange that this would have been changed in a stable release. It
> doesn't seem to have been a security update.
It looks like it's coming from this change:
https://metadata.ftp-master.debian.org/changelogs//main/s/sendmail/sendmail_8.17.1.9-2+deb12u2_changelog
* Fix CVE-2023-51765 (Closes: #1059386):
sendmail allowed SMTP smuggling in certain configurations.
Remote attackers can use a published exploitation
technique to inject e-mail messages with a spoofed
MAIL FROM address, allowing bypass of an SPF protection
mechanism. This occurs because sendmail supports
<LF>.<CR><LF> but some other popular e-mail servers
do not. This is resolved with 'o' in srv_features.
I don't know the details of how this leads to a security hole.
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