{"id":"UBUNTU-CVE-2018-18020","details":"In QPDF 8.2.1, in libqpdf/QPDFWriter.cc, QPDFWriter::unparseObject and QPDFWriter::unparseChild have recursive calls for a long time, which allows remote attackers to cause a denial of service via a crafted PDF file.","modified":"2026-04-22T11:49:20.048583Z","published":"2018-10-06T14:29:00Z","related":["USN-5026-1","USN-5026-2"],"upstream":["CVE-2018-18020"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2018-18020"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5026-1"},{"type":"ADVISORY","url":"https://ubuntu.com/security/notices/USN-5026-2"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2018-18020"}],"affected":[{"package":{"name":"qpdf","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/qpdf@8.0.2-3~16.04.1+esm1?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.0.2-3~16.04.1+esm1"}]}],"versions":["5.1.3-2","5.1.3-3","5.2.0-1","5.2.0-2","6.0.0-2","8.0.2-3~16.04.1"],"ecosystem_specific":{"binaries":[{"binary_version":"8.0.2-3~16.04.1+esm1","binary_name":"libqpdf21"},{"binary_version":"8.0.2-3~16.04.1+esm1","binary_name":"qpdf"}],"availability":"Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-18020.json"}},{"package":{"name":"qpdf","ecosystem":"Ubuntu:18.04:LTS","purl":"pkg:deb/ubuntu/qpdf@8.0.2-3ubuntu0.1?arch=source&distro=bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"8.0.2-3ubuntu0.1"}]}],"versions":["7.0.0-1","7.1.0-1","7.1.1-1","8.0.0-1","8.0.1-1","8.0.2-1","8.0.2-3"],"ecosystem_specific":{"binaries":[{"binary_version":"8.0.2-3ubuntu0.1","binary_name":"libqpdf21"},{"binary_version":"8.0.2-3ubuntu0.1","binary_name":"qpdf"}],"availability":"No subscription required"},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2018/UBUNTU-CVE-2018-18020.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.0/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L"},{"type":"Ubuntu","score":"low"}]}