{"id":"CVE-2018-11518","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-11518","generatedAt":"2026-10-28T21:22:51.984Z","title":"A vulnerability allows a phreaking attack on HCL legacy IVR systems that do not use VoIP.","description":"A vulnerability allows a phreaking attack on HCL legacy IVR systems that do not use VoIP. These IVR systems rely on various frequencies of audio signals; based on the frequency, certain commands and functions are processed. Since these frequencies are accepted within a phone call, an attacker can record these frequencies and use them for service activations. This is a request-forgery issue when the required series of DTMF signals for a service activation is predictable (e.g., the IVR system does not speak a nonce to the caller). In this case, the IVR system accepts an activation request from a less-secure channel (any loudspeaker in the caller's physical environment) without verifying that the request was intended (it matches a nonce sent over a more-secure channel to the caller's earpiece).","published":"2018-05-30T20:29:00.000Z","lastModified":"2026-06-17T01:36:06.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.0","score":8.1,"severity":"HIGH","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-20"],"affected":["hcltech/legacy ivr firmware"],"epss":{"score":0.01398,"percentile":0.72291,"date":"2026-10-27","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 (1.40%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"http://virgil-cj.blogspot.com/2018/05/0day-legacy-ivr-lets-phreak.html","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://datarift.blogspot.com/2018/05/CVE-2018-11518-abusing-ivr-systems.html","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://twitter.com/mishradhiraj_/status/1001664204485652482","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://twitter.com/mishradhiraj_/status/1001664440759091207","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"http://virgil-cj.blogspot.com/2018/05/0day-legacy-ivr-lets-phreak.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://datarift.blogspot.com/2018/05/CVE-2018-11518-abusing-ivr-systems.html","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://twitter.com/mishradhiraj_/status/1001664204485652482","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://twitter.com/mishradhiraj_/status/1001664440759091207","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-11518","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."}