{"id":"UBUNTU-CVE-2020-23856","details":"Use-after-Free vulnerability in cflow 1.6 in the void call(char *name, int line) function at src/parser.c, which could cause a denial of service via the pointer variable caller-\u003ecallee.","modified":"2026-05-20T16:06:22.188232339Z","published":"2021-05-18T15:15:00Z","upstream":["CVE-2020-23856"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2020-23856"},{"type":"REPORT","url":"https://lists.gnu.org/archive/html/bug-cflow/2020-07/msg00000.html"},{"type":"REPORT","url":"https://github.com/yangjiageng/PoC/blob/master/PoC_cflow_uaf_parser_line1284"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2020-23856"}],"affected":[{"package":{"name":"cflow","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=esm-apps%2Fxenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.4+dfsg1-3ubuntu1","1:1.4+dfsg1-3ubuntu1.16.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"cflow","binary_version":"1:1.4+dfsg1-3ubuntu1.16.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}},{"package":{"name":"cflow","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=esm-apps%2Fbionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.4+dfsg1-3ubuntu1","1:1.4+dfsg1-3ubuntu1.18.04.1~esm1"],"ecosystem_specific":{"binaries":[{"binary_name":"cflow","binary_version":"1:1.4+dfsg1-3ubuntu1.18.04.1~esm1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}},{"package":{"name":"cflow","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.6-4"],"ecosystem_specific":{"binaries":[{"binary_name":"cflow","binary_version":"1:1.6-4"},{"binary_version":"1:1.6-4","binary_name":"cflow-l10n"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}},{"package":{"name":"cflow","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.6-4","1:1.6-6","1:1.7-2"],"ecosystem_specific":{"binaries":[{"binary_name":"cflow","binary_version":"1:1.7-2"},{"binary_name":"cflow-l10n","binary_version":"1:1.7-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}},{"package":{"name":"cflow","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.7-4","1:1.7-5"],"ecosystem_specific":{"binaries":[{"binary_name":"cflow","binary_version":"1:1.7-5"},{"binary_name":"cflow-l10n","binary_version":"1:1.7-5"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}},{"package":{"name":"cflow","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.7-5","1:1.8-1"],"ecosystem_specific":{"binaries":[{"binary_name":"cflow","binary_version":"1:1.8-1"},{"binary_name":"cflow-l10n","binary_version":"1:1.8-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}},{"package":{"name":"cflow","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/cflow?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:1.8-1","1:1.8-1build1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:1.8-1build1","binary_name":"cflow"},{"binary_name":"cflow-l10n","binary_version":"1:1.8-1build1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2020/UBUNTU-CVE-2020-23856.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}