{"id":"UBUNTU-CVE-2021-26717","details":"An issue was discovered in Sangoma Asterisk 16.x before 16.16.1, 17.x before 17.9.2, and 18.x before 18.2.1 and Certified Asterisk before 16.8-cert6. When re-negotiating for T.38, if the initial remote response was delayed just enough, Asterisk would send both audio and T.38 in the SDP. If this happened, and the remote responded with a declined T.38 stream, then Asterisk would crash.","modified":"2026-05-20T16:06:26.706660101Z","published":"2021-02-18T20:15:00Z","upstream":["CVE-2021-26717"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-26717"},{"type":"REPORT","url":"http://packetstormsecurity.com/files/161471/Asterisk-Project-Security-Advisory-AST-2021-002.html"},{"type":"REPORT","url":"http://seclists.org/fulldisclosure/2021/Feb/58"},{"type":"REPORT","url":"https://downloads.asterisk.org/pub/security/"},{"type":"REPORT","url":"https://downloads.asterisk.org/pub/security/AST-2021-002.html"},{"type":"REPORT","url":"https://issues.asterisk.org/jira/browse/ASTERISK-29203"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-26717"}],"affected":[{"package":{"name":"asterisk","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/asterisk?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:16.16.1~dfsg-2","1:16.16.1~dfsg-4","1:16.16.1~dfsg-4build1","1:16.16.1~dfsg+~2.10-1","1:18.10.0~dfsg+~cs6.10.40431411-2"],"ecosystem_specific":{"binaries":[{"binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2","binary_name":"asterisk"},{"binary_name":"asterisk-config","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"},{"binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2","binary_name":"asterisk-dahdi"},{"binary_name":"asterisk-mobile","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"},{"binary_name":"asterisk-modules","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"},{"binary_name":"asterisk-mp3","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"},{"binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2","binary_name":"asterisk-mysql"},{"binary_name":"asterisk-ooh323","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"},{"binary_name":"asterisk-tests","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"},{"binary_name":"asterisk-vpb","binary_version":"1:18.10.0~dfsg+~cs6.10.40431411-2"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26717.json"}},{"package":{"name":"asterisk","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/asterisk?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:20.4.0~dfsg+~cs6.13.40431414-2","1:20.5.0~dfsg+~cs6.13.40431414-1","1:20.5.1~dfsg+~cs6.13.40431414-1","1:20.5.2~dfsg+~cs6.13.40431414-1","1:20.6.0~dfsg+~cs6.13.40431414-1","1:20.6.0~dfsg+~cs6.13.40431414-2","1:20.6.0~dfsg+~cs6.13.40431414-2build3","1:20.6.0~dfsg+~cs6.13.40431414-2build4","1:20.6.0~dfsg+~cs6.13.40431414-2build5"],"ecosystem_specific":{"binaries":[{"binary_name":"asterisk","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-config","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-dahdi","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-mobile","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-modules","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-mp3","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-mysql","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_name":"asterisk-ooh323","binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5"},{"binary_version":"1:20.6.0~dfsg+~cs6.13.40431414-2build5","binary_name":"asterisk-tests"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26717.json"}},{"package":{"name":"asterisk","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/asterisk?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:22.2.0~dfsg+~cs6.15.60671435-2","1:22.3.0~dfsg+~cs6.15.60671435-1","1:22.4.1~dfsg+~cs6.15.60671435-1","1:22.4.1~dfsg+~cs6.15.60671435-2","1:22.5.1~dfsg+~cs6.15.60671435-1","1:22.5.2~dfsg+~cs6.15.60671435-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk"},{"binary_name":"asterisk-config","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_name":"asterisk-dahdi","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_name":"asterisk-mobile","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk-modules"},{"binary_name":"asterisk-mp3","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_name":"asterisk-mysql","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_name":"asterisk-ooh323","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_name":"asterisk-tests","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26717.json"}},{"package":{"name":"asterisk","ecosystem":"Ubuntu:26.04:LTS","purl":"pkg:deb/ubuntu/asterisk?arch=source&distro=resolute"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1:22.5.2~dfsg+~cs6.15.60671435-1"],"ecosystem_specific":{"binaries":[{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk"},{"binary_name":"asterisk-config","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk-dahdi"},{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk-mobile"},{"binary_name":"asterisk-modules","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"},{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk-mp3"},{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk-mysql"},{"binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1","binary_name":"asterisk-ooh323"},{"binary_name":"asterisk-tests","binary_version":"1:22.5.2~dfsg+~cs6.15.60671435-1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26717.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},{"type":"Ubuntu","score":"medium"}]}