{"id":"CVE-2019-3556","url":"https://www.cyber-defence.io/tools/cve/CVE-2019-3556","generatedAt":"2026-10-27T22:23:36.378Z","title":"One of those request handlers, dump-pcre-cache, can be used to output cached regular expressions from the current execution context into a file.","description":"HHVM supports the use of an \"admin\" server which accepts administrative requests over HTTP. One of those request handlers, dump-pcre-cache, can be used to output cached regular expressions from the current execution context into a file. The handler takes a parameter which specifies where on the filesystem to write this data. The parameter is not validated, allowing a malicious user to overwrite arbitrary files where the user running HHVM has write access. This issue affects HHVM versions prior to 4.56.2, all versions between 4.57.0 and 4.78.0, as well as 4.79.0, 4.80.0, 4.81.0, 4.82.0, and 4.83.0.","published":"2021-10-26T20:15:08.000Z","lastModified":"2026-06-17T02:35:13.000Z","status":"Modified","sourceIdentifier":"cve-assign@fb.com","cvss":{"version":"3.1","score":8.1,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H"},"cwe":["CWE-22"],"affected":["facebook/hhvm"],"epss":{"score":0.01789,"percentile":0.78196,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (1.79%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/facebook/hhvm/commit/abe0b29e4d3a610f9bc920b8be4ad8403364c2d4","tags":["Patch","Third Party Advisory"],"source":"cve-assign@fb.com"},{"url":"https://hhvm.com/blog/2020/11/12/security-update.html","tags":["Vendor Advisory"],"source":"cve-assign@fb.com"},{"url":"https://www.facebook.com/security/advisories/cve-2019-3556","tags":["Broken Link"],"source":"cve-assign@fb.com"},{"url":"https://github.com/facebook/hhvm/commit/abe0b29e4d3a610f9bc920b8be4ad8403364c2d4","tags":["Patch","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://hhvm.com/blog/2020/11/12/security-update.html","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.facebook.com/security/advisories/cve-2019-3556","tags":["Broken Link"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2019-3556","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}