{"affected":[{"affectedData":[{"defaultStatus":"unaffected","product":"Cognos Controller","vendor":"IBM","versions":[{"status":"affected","version":"10.4.1, 10.4.2, 11.0.0"}]}],"source":"psirt@us.ibm.com"},{"affectedData":[{"cpes":["cpe:2.3:a:ibm:cognos_controller:10.4.1:*:*:*:*:*:*:*"],"defaultStatus":"unknown","product":"cognos_controller","vendor":"ibm","versions":[{"status":"affected","version":"10.4.1"}]},{"cpes":["cpe:2.3:a:ibm:cognos_controller:10.4.2:*:*:*:*:*:*:*"],"defaultStatus":"unknown","product":"cognos_controller","vendor":"ibm","versions":[{"status":"affected","version":"10.4.2"}]},{"cpes":["cpe:2.3:a:ibm:cognos_controller:11.0.0:*:*:*:*:*:*:*"],"defaultStatus":"unknown","product":"cognos_controller","vendor":"ibm","versions":[{"status":"affected","version":"11.0.0"}]}],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"configurations":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:a:ibm:cognos_controller:10.4.1:*:*:*:*:*:*:*","matchCriteriaId":"04E5A9C3-0F44-40C1-B6B6-92839E386F56","vulnerable":true},{"criteria":"cpe:2.3:a:ibm:cognos_controller:10.4.2:*:*:*:*:*:*:*","matchCriteriaId":"7AA07D9A-71F7-446A-8A8E-DD8C357666F0","vulnerable":true},{"criteria":"cpe:2.3:a:ibm:cognos_controller:11.0.0:*:*:*:*:*:*:*","matchCriteriaId":"4BB85020-BF02-4C91-B494-93FB19185006","vulnerable":true}],"negate":false,"operator":"OR"}]}],"cveTags":[],"descriptions":[{"lang":"en","value":"IBM Cognos Controller 10.4.1, 10.4.2, and 11.0.0 could allow a remote user to enumerate usernames due to differentiating error messages on existing usernames.  IBM X-Force ID:  199181."},{"lang":"es","value":"IBM Cognos Controller 10.4.1, 10.4.2 y 11.0.0 podrían permitir que un usuario remoto enumere nombres de usuarios debido a mensajes de error diferenciadores en nombres de usuarios existentes. ID de IBM X-Force: 199181."}],"id":"CVE-2021-20556","lastModified":"2026-06-17T03:34:00.853","metrics":{"cvssMetricV31":[{"cvssData":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"},"exploitabilityScore":3.9,"impactScore":1.4,"source":"psirt@us.ibm.com","type":"Secondary"},{"cvssData":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N","version":"3.1"},"exploitabilityScore":3.9,"impactScore":1.4,"source":"nvd@nist.gov","type":"Primary"}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"id":"CVE-2021-20556","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","timestamp":"2024-05-06T15:50:40.743794Z","version":"2.0.3"}}]},"published":"2024-05-03T18:15:07.907","references":[{"source":"psirt@us.ibm.com","tags":["Vendor Advisory"],"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/199181"},{"source":"psirt@us.ibm.com","tags":["Vendor Advisory"],"url":"https://www.ibm.com/support/pages/node/7149876"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Vendor Advisory"],"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/199181"},{"source":"af854a3a-2127-422b-91ae-364da2661108","tags":["Vendor Advisory"],"url":"https://www.ibm.com/support/pages/node/7149876"}],"sourceIdentifier":"psirt@us.ibm.com","vulnStatus":"Analyzed","weaknesses":[{"description":[{"lang":"en","value":"CWE-204"}],"source":"psirt@us.ibm.com","type":"Secondary"},{"description":[{"lang":"en","value":"CWE-203"}],"source":"nvd@nist.gov","type":"Primary"}]}