Vulnerability Details CVE-2021-28543
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.009
EPSS Ranking 74.9%
CVSS Severity
CVSS v3 Score 4.0
CVSS v2 Score 5.0
References
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPFBRQUJNWHCB3GQHSSAPRLQU6Q6PY43/
- https://varnish-cache.org/security/VSV00006.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPFBRQUJNWHCB3GQHSSAPRLQU6Q6PY43/
- https://varnish-cache.org/security/VSV00006.html
Products affected by CVE-2021-28543
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cpe:2.3:a:varnish-cache:varnish-modules:*
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cpe:2.3:a:varnish-cache:varnish-modules_klarlack:*
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cpe:2.3:o:fedoraproject:fedora:34