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HighFix available

User impersonation due to incorrect handling of the login JWT

Type: advisorySource: OSV1 source record

### Impact This allows anyone that can connect to the server to forge a LoginPacket with manipulated JWT token allowing impersonation as any Bedrock user. Unless credentials are saved in your configuration, online mode is not affected as users are still required to log in separately. If your credentials are saved, there is no risk of exposing your email or password. ### Patches This was patched as part of https://github.com/GeyserMC/Geyser/commit/b9541505af68ac7b7c093206ac7b1ba88957a5a6 and https://github.com/GeyserMC/Geyser/commit/ab2f5b326fe590e09167e8b45b4b165ac06ecd13. if your Geyser version is `1.4.2-SNAPSHOT` or later, the issue has been addressed on your build. ### Workarounds Geyser strongly recommends updating to fix this issue. If this isn't possible: - Use online mode and don't save credentials in your Geyser configuration - Use an additional authentication method on the Java server ### References This was disclosed to us by a staff member over at Hive; you can read their disclosure here: https://updates.playhive.com/changelog/weekend-maintenance-breakdown ### For more information If you have any questions or comments about this advisory: * Come talk to us over on our [Discord](https://discord.gg/geysermc) server in the [#development](https://discord.com/channels/613163671870242838/613170125696270357) channel

Announced Source revision 1
Original source ↗

GHSA-h77f-xxx7-4858

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:GHSA-h77f-xxx7-4858

org.geysermc:connector

Source reference: /affected/0/package/name

Affected versions
Not stated in this record
Fixed versions
1.4.2-SNAPSHOT

Source reference: /affected/0/ranges

Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "1.4.2-SNAPSHOT"
          }
        ]
      }
    ],
    "package": {
      "name": "org.geysermc:connector",
      "purl": "pkg:maven/org.geysermc/connector",
      "ecosystem": "Maven"
    },
    "database_specific": {
      "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2021/09/GHSA-h77f-xxx7-4858/GHSA-h77f-xxx7-4858.json"
    }
  }
]
Related CVEs
CVE-2021-39177

Source reference: /aliases

Publisher severity

high

Source reference: /database_specific/severity

Event
#63799 · Revision 1
Added to Heist Feed
Publisher date
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