CVE-2021-28543 Null dereference in n/a
Remote attackers can cause a denial of service by triggering a null pointer dereference in Varnish Cache modules, leading to daemon restarts.
- 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-2021-28543?
CVE-2021-28543 is a medium-severity vulnerability in Fedoraproject Fedora, published on 16 Mar 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Varnish varnish-modules before 0.17.1 allows remote attackers to cause a denial of service (daemon restart) in some configurations. This does not affect organizations that only install the Varnish Cache product; however, it is common to install both Varnish Cache and varnish-modules. Specifically, an assertion failure or NULL pointer dereference can be triggered in Varnish Cache through the varnish-modules header.append() and header.copy() functions. For some Varnish Configuration Language (VCL) files, this gives remote clients an opportunity to cause a Varnish Cache restart. A restart reduces overall availability and performance due to an increased number of cache misses, and may cause higher load on backend servers.
Which versions are affected by CVE-2021-28543?
It affects 3 products.
Products include Fedoraproject Fedora, Varnish-Cache Varnish-Modules, Varnish-Cache Varnish-Modules Klarlack.
How do I fix CVE-2021-28543?
No fix has been published for CVE-2021-28543 yet. Limit exposure of the affected software until one is available.
Is CVE-2021-28543 being exploited?
There is no known exploitation of CVE-2021-28543 in the wild and no public exploit code.
Other vulnerabilities in Fedoraproject Fedora
Sources
Also known as GHSA-jpm5-7xh4-qgjv.