{"id":"CVE-2021-28543","state":"PUBLISHED","title":"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 ins","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.","publishedAt":"2021-03-16T14:43:04.000Z","updatedAt":"2024-08-03T21:47:32.984Z","severity":{"score":4,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AC:H/AV:N/A:L/C:N/I:N/PR:N/S:C/UI:N","source":"mitre"},"assigner":"mitre","products":["n/a n/a"],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":["https://varnish-cache.org/security/VSV00006.html","https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPFBRQUJNWHCB3GQHSSAPRLQU6Q6PY43/"],"weaknesses":[],"ingestedAt":"2026-10-29T19:48:19.096Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/28xxx/CVE-2021-28543.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.1","cveMetadata":{"cveId":"CVE-2021-28543","state":"PUBLISHED","datePublished":"2021-03-16T14:43:04.000Z","dateUpdated":"2024-08-03T21:47:32.984Z","assignerShortName":"mitre","assignerOrgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca","dateReserved":"2021-03-16T00:00:00.000Z"},"containers":{"cna":{"descriptions":[{"lang":"en","value":"Varnish varnish-modules before 0.17.1 allows remote attackers to cause a denial of service (daemon restart) in some configurations. 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A restart reduces overall availability and performance due to an increased number of cache misses, and may cause higher load on backend servers."}],"affected":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}],"references":[{"url":"https://varnish-cache.org/security/VSV00006.html","tags":["x_refsource_MISC"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OPFBRQUJNWHCB3GQHSSAPRLQU6Q6PY43/","name":"FEDORA-2021-2ad352ec70","tags":["vendor-advisory","x_refsource_FEDORA"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":4,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AC:H/AV:N/A:L/C:N/I:N/PR:N/S:C/UI:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"description":"n/a","lang":"en","type":"text"}]}],"providerMetadata":{"shortName":"mitre","dateUpdated":"2021-03-22T03:06:12.000Z","orgId":"8254265b-2729-46b6-b9e3-3dfca2d5bfca"},"x_legacyV4Record":{"CVE_data_meta":{"ASSIGNER":"cve@mitre.org","ID":"CVE-2021-28543","STATE":"PUBLIC"},"affects":{"vendor":{"vendor_data":[{"product":{"product_data":[{"product_name":"n/a","version":{"version_data":[{"version_value":"n/a"}]}}]},"vendor_name":"n/a"}]}},"data_format":"MITRE","data_type":"CVE","data_version":"4.0","description":{"description_data":[{"lang":"eng","value":"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. 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