{"id":"CVE-2021-34823","aliases":["EUVD-2021-21470","GHSA-ff42-ccp4-hwcv"],"status":"published","title":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file...","description":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file access via its built-in HTTP server. This allows unauthenticated remote users to retrieve files accessible to the logged-on macOS user. When a remote user sends a crafted HTTP request to the server, it triggers a code path that will download a configuration file from a specified remote machine over HTTP. There is an XXE flaw in processing of this configuration file that allows reading local (to macOS) files and uploading them to remote machines.","severity":{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-10","score":0.01979,"percentile":0.807,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-611"],"published":"2021-08-13T16:48:09Z","modified":"2026-06-17T03:56:37Z","products":[{"vendor":"on24","product":"screenshare"}],"references":[{"url":"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"https://www.trustwave.com/en-us/resources/security-resources/security-advisories/?fid=29105","tags":["x_refsource_MISC","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-34823"},{"url":"https://github.com/advisories/GHSA-ff42-ccp4-hwcv"}],"sources":{"cve":[{"id":"CVE-2021-34823","description":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file access via its built-in HTTP server. This allows unauthenticated remote users to retrieve files accessible to the logged-on macOS user. When a remote user sends a crafted HTTP request to the server, it triggers a code path that will download a configuration file from a specified remote machine over HTTP. There is an XXE flaw in processing of this configuration file that allows reading local (to macOS) files and uploading them to remote machines.","status":"published","published":"2021-08-13T16:48:09Z","modified":"2024-08-04T00:26:54.032Z","updated_at":"2026-11-02T14:33:11.244759Z"}],"euvd":[{"id":"EUVD-2021-21470","description":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file access via its built-in HTTP server. This allows unauthenticated remote users to retrieve files accessible to the logged-on macOS user. When a remote user sends a crafted HTTP request to the server, it triggers a code path that will download a configuration file from a specified remote machine over HTTP. There is an XXE flaw in processing of this configuration file that allows reading local (to macOS) files and uploading them to remote machines.","status":"published","published":"2021-08-13T16:48:09Z","modified":"2024-08-04T00:26:54Z","updated_at":"2026-11-03T03:24:31.977228Z"}],"ghsa":[{"id":"GHSA-ff42-ccp4-hwcv","title":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file...","description":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file access via its built-in HTTP server. This allows unauthenticated remote users to retrieve files accessible to the logged-on macOS user. When a remote user sends a crafted HTTP request to the server, it triggers a code path that will download a configuration file from a specified remote machine over HTTP. There is an XXE flaw in processing of this configuration file that allows reading local (to macOS) files and uploading them to remote machines.","status":"published","published":"2022-05-24T19:11:03Z","modified":"2023-01-30T05:01:30Z","cwes":["CWE-611"],"updated_at":"2026-11-02T14:46:25.569206Z"}],"nvd":[{"id":"CVE-2021-34823","description":"The ON24 ScreenShare (aka DesktopScreenShare.app) plugin before 2.0 for macOS allows remote file access via its built-in HTTP server. This allows unauthenticated remote users to retrieve files accessible to the logged-on macOS user. When a remote user sends a crafted HTTP request to the server, it triggers a code path that will download a configuration file from a specified remote machine over HTTP. There is an XXE flaw in processing of this configuration file that allows reading local (to macOS) files and uploading them to remote machines.","status":"published","published":"2021-08-13T17:15:16.527Z","modified":"2026-06-17T03:56:37.763Z","cvss":[{"version":"3.1","score":9.1,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N","level":"critical","assessor":"primary"},{"version":"2.0","score":6.4,"vector":"AV:N/AC:L/Au:N/C:P/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-611"],"updated_at":"2026-11-02T14:06:56.943671Z"}]}}