CVE-2021-35525 Denial of service in n/a
An attacker can cause a denial of service by triggering a subprocess hang in PostSRSd via long data fields from Postfix.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2021-35525?
CVE-2021-35525 is a medium-severity denial of service vulnerability in n/a, published on 28 Jun 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
PostSRSd before 1.11 allows a denial of service (subprocess hang) if Postfix sends certain long data fields such as multiple concatenated email addresses. NOTE: the PostSRSd maintainer acknowledges "theoretically, this error should never occur ... I'm not sure if there's a reliable way to trigger this condition by an external attacker, but it is a security bug in PostSRSd nevertheless."
Which versions are affected by CVE-2021-35525?
It affects 1 product.
Products include Postsrsd Project Postsrsd.
How do I fix CVE-2021-35525?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-35525 being exploited?
There is no known exploitation of CVE-2021-35525 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2021-35525, GHSA-w799-rf9r-4rqc, UBUNTU-CVE-2021-35525.