{"schema_version":"public-product-v1.1","generated_at":"2026-07-21T10:01:29Z","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","advisory":{"id":"cisco-sa-airo-wpa-pktleak-dos-uSTyGrL","slug":"cisco-sa-airo-wpa-pktleak-dos-ustygrl","vendor":"Cisco","title":"Cisco Aironet Access Points WLAN Control Protocol Packet Buffer Leak Denial of Service Vulnerability","summary":"A vulnerability in the WLAN Control Protocol (WCP) implementation for Cisco Aironet Access Point (AP) software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition.  This vulnerability is due to incorrect error handling when an affected device receives an unexpected 802.11 frame. An attacker could exploit this vulnerability by sending certain 802.11 frames over the wireless network to an interface on an affected AP. A successful exploit could allow the attacker to cause a packet buffer leak. This could eventually result in buffer allocation failures, which would trigger a reload of the affected device. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability. This advisory is available at the following link:https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL","severity":"High","published_at":"2021-09-22T16:00:00Z","updated_at":"2021-09-22T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL","csaf_url":"https://sec.cloudapps.cisco.com/security/center/contentjson/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL/csaf/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL.json","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure."},"freshness":{"last_source_refreshed_at":"2026-07-21T05:16:34Z","latest_source_refresh_at":"2026-07-21T05:16:34Z","oldest_source_refresh_at":"2026-07-21T03:00:03Z","all_sources_fresh":true,"sources":[{"source":"cisco_advisories","label":"Cisco advisories","last_success_at":"2026-07-21T03:00:03Z","stale":false},{"source":"cisco_csaf","label":"Cisco CSAF","last_success_at":"2026-07-21T05:14:24Z","stale":false},{"source":"nvd_cves","label":"NVD CVEs","last_success_at":"2026-07-21T05:16:30Z","stale":false},{"source":"cisa_kev","label":"CISA KEV","last_success_at":"2026-07-21T05:16:31Z","stale":false},{"source":"first_epss","label":"EPSS","last_success_at":"2026-07-21T05:16:34Z","stale":false}]},"summary":{"cve_count":1,"visible_product_count":2,"public_evidence_count":2,"kev_count":0,"highest_epss":0.0036},"cves":[{"id":"CVE-2021-34740","kev":false,"epss":{"score":0.0036,"percentile":0.28376,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"}}],"public_evidence":[{"product":{"name":"Cisco Aironet Access Point Software","slug":"cisco-aironet-access-point-software","vendor":"Cisco"},"cve":{"id":"CVE-2021-34740"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-19T23:33:14Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco Aironet Access Point Software","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.0036,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-09-22T16:00:00Z","updated_at":"2021-09-22T16:00:00Z","advisory_updated_at":"2021-09-22T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL"},"row_display_order":1},{"product":{"name":"Cisco Aironet Access Point Software (IOS XE Controller)","slug":"cisco-aironet-access-point-software-ios-xe-controller","vendor":"Cisco"},"cve":{"id":"CVE-2021-34740"},"evidence_type":"structured_affected","evidence_label":{"scope":"CSAF product evidence","label":"product_status known affected"},"evidence_source":"Cisco CSAF","source":"Cisco CSAF","source_document_fetched_at":"2026-07-19T23:33:14Z","csaf_status":"known_affected","csaf_product_status":"known_affected","csaf_product_status_path":"vulnerabilities[].product_status.known_affected","raw_product_name":"Cisco Aironet Access Point Software (IOS XE Controller)","exposure_verdict":"not_assessed","verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","exposure_verdict_reason":"Public evidence does not evaluate exact release, platform, enabled features, configuration, compensating controls, or live exposure.","kev":false,"epss":{"score":0.0036,"score_date":"2026-07-20","updated_at":"2026-07-21T05:16:34Z"},"published_at":"2021-09-22T16:00:00Z","updated_at":"2021-09-22T16:00:00Z","advisory_updated_at":"2021-09-22T16:00:00Z","source_url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL","remediation":{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-airo-wpa-pktleak-dos-uSTyGrL"},"row_display_order":2}]}