{"vulnerability": "CVE-2021-39840", "sightings": [{"uuid": "1beda80a-6358-45fb-a7bb-b49bc46b950f", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "seen", "source": "https://t.me/arpsyndicate/182", "content": "#ExploitObserverAlert\n\nCVE-2021-39840\n\nDESCRIPTION: Exploit Observer has 1 entries related to CVE-2021-39840. Acrobat Reader DC versions 2021.005.20060 (and earlier), 2020.004.30006 (and earlier) and 2017.011.30199 (and earlier) are affected by a use-after-free vulnerability when processing AcroForms that could result in arbitrary code execution in the context of the current user. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.\n\nFIRST-EPSS: 0.365760000\nNVD-IS: 6.4\nNVD-ES: 8.6", "creation_timestamp": "2023-11-17T02:43:04.000000Z"}, {"uuid": "8a53929c-df89-414f-8ae4-3383bdf29905", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "published-proof-of-concept", "source": "https://t.me/CyberSecurityTechnologies/4575", "content": "#exploit\nCVE-2021-28632, CVE-2021-39840:\nBypassing Locks in Adobe Reader\nhttps://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader", "creation_timestamp": "2021-10-22T11:03:01.000000Z"}, {"uuid": "5225876b-e4ec-4692-ba09-f61cef158582", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "published-proof-of-concept", "source": "https://t.me/reverseame/1725", "content": "CVE-2021-28632 & CVE-2021-39840: Bypassing Locks in Adobe Reader https://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader", "creation_timestamp": "2026-08-03T05:00:04.597385Z"}, {"uuid": "afdeb8b5-b3b3-457a-8ce2-d4fbe4f9b09f", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "published-proof-of-concept", "source": "https://t.me/reverseame/1725", "content": "CVE-2021-28632 & CVE-2021-39840: Bypassing Locks in Adobe Reader https://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader", "creation_timestamp": "2026-08-04T00:00:50.047649Z"}, {"uuid": "200102a5-5b31-4197-a7b1-961f73c64d85", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "seen", "source": "https://t.me/reverseame/1725", "content": "CVE-2021-28632 & CVE-2021-39840: Bypassing Locks in Adobe Reader https://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader", "creation_timestamp": "2026-07-29T12:02:52.289557Z"}, {"uuid": "2f164557-9c2c-435b-bfb5-605c560fce30", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "seen", "source": "https://t.me/reverseame/1725", "content": "CVE-2021-28632 & CVE-2021-39840: Bypassing Locks in Adobe Reader https://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader", "creation_timestamp": "2026-07-30T00:02:42.745917Z"}, {"uuid": "11d394c2-1f3d-4a27-982c-190032836337", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "seen", "source": "https://t.me/cissp/4666", "content": "Threat Research\nUsing Kerberos for Authentication Relay Attacks\nhttps://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html\n\nSuDump: Exploiting suid binaries through the kernel\n(LPE through the sudo program)\nhttps://alephsecurity.com/2021/10/20/sudump\n\nexploit\nCVE-2021-28632, CVE-2021-39840:\nBypassing Locks in Adobe Reader\nhttps://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader\n\nOffensive security\nCobalt Strike: Using Known Private Keys To Decrypt Traffic - Part 1\nhttps://blog.nviso.eu/2021/10/21/cobalt-strike-using-known-private-keys-to-decrypt-traffic-part-1\n\n\n\u200e", "creation_timestamp": "2026-09-01T17:00:37.572569Z"}, {"uuid": "9758a93f-a538-41cb-a40d-30cfa2bff1a3", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "seen", "source": "https://t.me/cissp/4666", "content": "Threat Research\nUsing Kerberos for Authentication Relay Attacks\nhttps://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html\n\nSuDump: Exploiting suid binaries through the kernel\n(LPE through the sudo program)\nhttps://alephsecurity.com/2021/10/20/sudump\n\nexploit\nCVE-2021-28632, CVE-2021-39840:\nBypassing Locks in Adobe Reader\nhttps://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader\n\nOffensive security\nCobalt Strike: Using Known Private Keys To Decrypt Traffic - Part 1\nhttps://blog.nviso.eu/2021/10/21/cobalt-strike-using-known-private-keys-to-decrypt-traffic-part-1\n\n\n\u200e", "creation_timestamp": "2026-09-02T01:04:22.332510Z"}, {"uuid": "73fcd3dd-5ebf-4170-aac2-a029de1ea8bf", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "published-proof-of-concept", "source": "https://t.me/cissp/4666", "content": "Threat Research\nUsing Kerberos for Authentication Relay Attacks\nhttps://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html\n\nSuDump: Exploiting suid binaries through the kernel\n(LPE through the sudo program)\nhttps://alephsecurity.com/2021/10/20/sudump\n\nexploit\nCVE-2021-28632, CVE-2021-39840:\nBypassing Locks in Adobe Reader\nhttps://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader\n\nOffensive security\nCobalt Strike: Using Known Private Keys To Decrypt Traffic - Part 1\nhttps://blog.nviso.eu/2021/10/21/cobalt-strike-using-known-private-keys-to-decrypt-traffic-part-1\n\n\n\u200e", "creation_timestamp": "2026-09-10T16:00:04.706459Z"}, {"uuid": "ec04e360-5c16-4051-9491-01236721a7f4", "vulnerability_lookup_origin": "1a89b78e-f703-45f3-bb86-59eb712668bd", "author": "9f56dd64-161d-43a6-b9c3-555944290a09", "vulnerability": "CVE-2021-39840", "type": "published-proof-of-concept", "source": "https://t.me/cissp/4666", "content": "Threat Research\nUsing Kerberos for Authentication Relay Attacks\nhttps://googleprojectzero.blogspot.com/2021/10/using-kerberos-for-authentication-relay.html\n\nSuDump: Exploiting suid binaries through the kernel\n(LPE through the sudo program)\nhttps://alephsecurity.com/2021/10/20/sudump\n\nexploit\nCVE-2021-28632, CVE-2021-39840:\nBypassing Locks in Adobe Reader\nhttps://www.zerodayinitiative.com/blog/2021/10/20/cve-2021-28632-amp-cve-2021-39840-bypassing-locks-in-adobe-reader\n\nOffensive security\nCobalt Strike: Using Known Private Keys To Decrypt Traffic - Part 1\nhttps://blog.nviso.eu/2021/10/21/cobalt-strike-using-known-private-keys-to-decrypt-traffic-part-1\n\n\n\u200e", "creation_timestamp": "2026-09-11T00:00:33.696094Z"}]}