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CVE-2018-5225: Atlassian Bitbucket: Remote code execution

CVE-2018-5225 is rated critical with a CVSS v3.0 base score of 9.9 and affects Atlassian Bitbucket. Per its scoring, it can be exploited over the network, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

In browser editing in Atlassian Bitbucket Server from version 4.13.0 before 5.4.8 (the fixed version for 4.13.0 through 5.4.7), 5.5.0 before 5.5.8 (the fixed version for 5.5.x), 5.6.0 before 5.6.5 (the fixed version for 5.6.x), 5.7.0 before 5.7.3 (the fixed version for 5.7.x), and 5.8.0 before 5.8.2 (the fixed version for 5.8.x), allows authenticated users to gain remote code execution using the in browser editing feature via editing a symbolic link within a repository.

Severity breakdown

CVSS v3.0 9.9: CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

  • Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
  • Attack complexity: Low. No special conditions; the attack can be repeated reliably.
  • Privileges required: Low. A basic user account is enough.
  • User interaction: None. No action from any user is needed.
  • Scope: Changed. Impact reaches beyond the vulnerable component to other resources.
  • Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
  • Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
  • Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-59: Improper Link Resolution Before File Access

The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.

Affected products

  • Atlassian Bitbucket: from 4.13.0 before 5.4.8; after 5.5.0 before 5.5.8; from 5.6.0 before 5.6.5; from 5.7.0 before 5.7.3; from 5.8.0 before 5.8.2

References