{"id":"CVE-2021-3761","aliases":["DEBIAN-CVE-2021-3761","DSA-5041-1","EUVD-2021-2036","GHSA-c8xp-8mf3-62h9","GO-2022-0246","UBUNTU-CVE-2021-3761"],"status":"published","title":"OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.01216,"percentile":0.68971,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-295","CWE-787"],"published":"2021-09-07T23:02:18Z","modified":"2026-10-23T18:03:30Z","fixes":[{"ecosystem":"Go","package":"github.com/cloudflare/cfrpki","fixed_in":["1.3.0"],"sources":["ghsa","osv"]},{"ecosystem":"Debian:12","package":"cfrpki","fixed_in":["1.3.0-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"Go","package":"github.com/cloudflare/cfrpki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"cfrpki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.3.0-1"}]}]},{"source":"osv","ecosystem":"Debian:11","package":"cfrpki","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.4.2-1~deb11u1"}]}],"versions":["1.2.2-1","1.3.0-1","1.4.0-1"],"bundled":10},{"source":"osv","ecosystem":"Go","package":"github.com/cloudflare/cfrpki","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.3.0"}]}]},{"source":"osv","ecosystem":"Go","package":"github.com/cloudflare/cfrpki","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"fixed":"1.3.0"}]}]}],"products":[{"vendor":"cloudflare","product":"octorpki"},{"vendor":"debian","product":"debian_linux"}],"references":[{"url":"https://github.com/cloudflare/cfrpki/security/advisories/GHSA-c8xp-8mf3-62h9","tags":["x_refsource_MISC","x_transferred","Patch","Third Party Advisory","fix","web","report"]},{"url":"https://www.debian.org/security/2022/dsa-5041","tags":["vendor-advisory","x_refsource_DEBIAN","x_transferred","Third Party Advisory","advisory","web"]},{"url":"https://github.com/cloudflare/cfrpki/commit/a8db4e009ef217484598ba1fd1c595b54e0f6422","tags":["web","fix","report"]},{"url":"https://github.com/cloudflare/cfrpki/releases/tag/v1.3.0","tags":["web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-3761","tags":["advisory"]},{"url":"https://github.com/cloudflare/cfrpki/pull/90","tags":["web","fix"]},{"url":"https://pkg.go.dev/vuln/GO-2022-0246","tags":["web"]},{"url":"https://github.com/advisories/GHSA-c8xp-8mf3-62h9"},{"url":"https://security-tracker.debian.org/tracker/CVE-2021-3761","tags":["advisory"]},{"url":"github.com/cloudflare/cfrpki","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2021-3761","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2021-3761","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2021-3761","title":"OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","status":"published","published":"2021-09-09T14:05:09.349Z","modified":"2024-09-17T02:56:31.062Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"updated_at":"2026-11-02T14:33:04.020035Z"}],"euvd":[{"id":"EUVD-2021-2036","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","status":"published","published":"2021-09-09T14:05:09Z","modified":"2024-09-17T02:56:31Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:28:35.984836Z"}],"ghsa":[{"id":"GHSA-c8xp-8mf3-62h9","title":"OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to https://github.com/cloudflare/cfrpki/commit/a8db4e009ef217484598ba1fd1c595b54e0f6422 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. \n\n### Impact\n\nAn attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.\n\n### Patches\nhttps://github.com/cloudflare/cfrpki/commit/a8db4e009ef217484598ba1fd1c595b54e0f6422\n\nhttps://github.com/cloudflare/cfrpki/releases/tag/v1.3.0\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [security@cloudflare.com](security@cloudflare.com)\n","status":"published","published":"2021-09-07T23:02:18Z","modified":"2023-02-14T17:45:21Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-295","CWE-787"],"updated_at":"2026-11-02T14:36:45.67005Z"}],"nvd":[{"id":"CVE-2021-3761","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","status":"published","published":"2021-09-09T14:15:09.397Z","modified":"2026-06-17T04:05:42.9Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-787"],"updated_at":"2026-11-02T14:06:58.502206Z"}],"osv":[{"id":"CVE-2021-3761","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","status":"published","published":"2021-09-09T14:15:09.397Z","modified":"2026-10-20T10:54:49.800034748Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:44:20.434873Z"},{"id":"DEBIAN-CVE-2021-3761","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","status":"published","published":"2021-09-09T14:15:09.397Z","modified":"2026-10-23T18:03:30.501263226Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:35.521549Z"},{"id":"GHSA-c8xp-8mf3-62h9","title":"OctoRPKI lacks contextual out-of-bounds check when validating RPKI ROA maxLength values","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to https://github.com/cloudflare/cfrpki/commit/a8db4e009ef217484598ba1fd1c595b54e0f6422 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. \n\n### Impact\n\nAn attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.\n\n### Patches\nhttps://github.com/cloudflare/cfrpki/commit/a8db4e009ef217484598ba1fd1c595b54e0f6422\n\nhttps://github.com/cloudflare/cfrpki/releases/tag/v1.3.0\n\n### For more information\nIf you have any questions or comments about this advisory:\n* Email us at [security@cloudflare.com](security@cloudflare.com)\n","status":"published","published":"2021-09-07T23:02:18Z","modified":"2026-07-08T06:27:57.548504664Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-295","CWE-787"],"updated_at":"2026-11-02T15:46:44.927642Z"},{"id":"UBUNTU-CVE-2021-3761","description":"Any CA issuer in the RPKI can trick OctoRPKI prior to 1.3.0 into emitting an invalid VRP \"MaxLength\" value, causing RTR sessions to terminate. An attacker can use this to disable RPKI Origin Validation in a victim network (for example AS 13335 - Cloudflare) prior to launching a BGP hijack which during normal operations would be rejected as \"RPKI invalid\". Additionally, in certain deployments RTR session flapping in and of itself also could cause BGP routing churn, causing availability issues.","status":"withdrawn","published":"2021-09-09T14:15:00Z","modified":"2025-07-16T07:43:00.945278Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:54:28.526929Z"},{"id":"DSA-5041-1","title":"cfrpki - security update","status":"published","published":"2022-01-11T00:00:00Z","modified":"2026-03-09T02:10:29.476256Z","updated_at":"2026-11-02T15:46:17.543497Z"},{"id":"GO-2022-0246","title":"Insufficient validation in github.com/cloudflare/cfrpki","description":"The ROAEntry.Validate function fails to perform bounds checks on the MaxLength field, allowing invalid values to pass validation.","status":"published","published":"2022-07-15T23:06:38Z","modified":"2024-05-20T16:03:47Z","updated_at":"2026-11-02T15:47:00.604718Z"}]}}