CVE-2020-12063 Security feature bypass in n/a
Attackers can bypass sender login restrictions in Postfix by using homoglyph characters in email addresses, allowing spoofed outbound messages.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2020-12063?
CVE-2020-12063 is a medium-severity vulnerability in n/a, published on 24 Apr 2020. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A certain Postfix 2.10.1-7 package could allow an attacker to send an email from an arbitrary-looking sender via a homoglyph attack, as demonstrated by the similarity of \xce\xbf to the 'o' character. This is potentially relevant when the /etc/postfix/sender_login feature is used, because a spoofed outbound message that uses a configured sender address is blocked with a "Sender address rejected: not logged in" error message, but a spoofed outbound message that uses a homoglyph of a configured sender address is not blocked. NOTE: some third parties argue that any missed blocking of spoofed outbound messages - except for exact matches to a sender address in the /etc/postfix/sender_login file - is outside the design goals of Postfix and thus cannot be considered a Postfix vulnerability
Which versions are affected by CVE-2020-12063?
It affects 1 product.
Products include Postfix Postfix.
How do I fix CVE-2020-12063?
No fix has been published for CVE-2020-12063 yet. Limit exposure of the affected software until one is available.
Is CVE-2020-12063 being exploited?
There is no known exploitation of CVE-2020-12063 in the wild and no public exploit code.
Other vulnerabilities in n/a
Sources
Also known as GHSA-5wj2-9pm2-74vm.