CVE-2021-43802

CVSS V2 High 9 CVSS V3 High 8.8
Description
Etherpad is a real-time collaborative editor. In versions prior to 1.8.16, an attacker can craft an `*.etherpad` file that, when imported, might allow the attacker to gain admin privileges for the Etherpad instance. This, in turn, can be used to install a malicious Etherpad plugin that can execute arbitrary code (including system commands). To gain privileges, the attacker must be able to trigger deletion of `express-session` state or wait for old `express-session` state to be cleaned up. Core Etherpad does not delete any `express-session` state, so the only known attacks require either a plugin that can delete session state or a custom cleanup process (such as a cron job that deletes old `sessionstorage:*` records). The problem has been fixed in version 1.8.16. If users cannot upgrade to 1.8.16 or install patches manually, several workarounds are available. Users may configure their reverse proxies to reject requests to `/p/*/import`, which will block all imports, not just `*.etherpad` imports; limit all users to read-only access; and/or prevent the reuse of `express_sid` cookie values that refer to deleted express-session state. More detailed information and general mitigation strategies may be found in the GitHub Security Advisory.
Overview
  • CVE ID
  • CVE-2021-43802
  • Assigner
  • security-advisories@github.com
  • Vulnerability Status
  • Analyzed
  • Published Version
  • 2021-12-09T23:15:07
  • Last Modified Date
  • 2021-12-15T15:03:16
CPE Configuration (Product)
CPE Vulnerable Operator Version Start Version End
cpe:2.3:a:etherpad:etherpad:*:*:*:*:*:*:*:* 1 OR 1.8.16
CVSS Version 2
  • Version
  • 2.0
  • Vector String
  • AV:N/AC:L/Au:S/C:C/I:C/A:C
  • Access Vector
  • NETWORK
  • Access Compatibility
  • LOW
  • Authentication
  • SINGLE
  • Confidentiality Impact
  • COMPLETE
  • Integrity Impact
  • COMPLETE
  • Availability Impact
  • COMPLETE
  • Base Score
  • 9
  • Severity
  • HIGH
  • Exploitability Score
  • 8
  • Impact Score
  • 10
CVSS Version 3
  • Version
  • 3.1
  • Vector String
  • CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • Attack Vector
  • NETWORK
  • Attack Compatibility
  • LOW
  • Privileges Required
  • LOW
  • User Interaction
  • NONE
  • Scope
  • UNCHANGED
  • Confidentiality Impact
  • HIGH
  • Availability Impact
  • HIGH
  • Base Score
  • 8.8
  • Base Severity
  • HIGH
  • Exploitability Score
  • 2.8
  • Impact Score
  • 5.9
History
Created Old Value New Value Data Type Notes
2022-05-10 06:41:14 Added to TrackCVE
2022-12-06 03:30:59 2021-12-09T23:15Z 2021-12-09T23:15:07 CVE Published Date updated
2022-12-06 03:30:59 2021-12-15T15:03:16 CVE Modified Date updated
2022-12-06 03:30:59 Analyzed Vulnerability Status updated