CVE-2018-16466 - Improper Check for Dropped Privileges

Severity

55%

Complexity

80%

Confidentiality

81%

Improper revalidation of permissions in Nextcloud Server prior to 14.0.0, 13.0.6 and 12.0.11 lead to not accepting access restrictions by acess tokens.

Improper revalidation of permissions in Nextcloud Server prior to 14.0.0, 13.0.6 and 12.0.11 lead to not accepting access restrictions by acess tokens.

CVSS 3.0 Base Score 8.1. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N).

CVSS 2.0 Base Score 5.5. CVSS Attack Vector: network. CVSS Attack Complexity: low. CVSS Vector: (AV:N/AC:L/Au:S/C:P/I:P/A:N).

Demo Examples

Improper Check for Dropped Privileges

CWE-273

This code attempts to take on the privileges of a user before creating a file, thus avoiding performing the action with unnecessarily high privileges:


               
}
/../

The call to ImpersonateNamedPipeClient may fail, but the return value is not checked. If the call fails, the code may execute with higher privileges than intended. In this case, an attacker could exploit this behavior to write a file to a location that the attacker does not have access to.

Overview

Type

Nextcloud Server 14.0.0

First reported 6 years ago

2018-10-30 21:29:00

Last updated 5 years ago

2019-10-09 23:36:00

Affected Software

Nextcloud Server 14.0.0 Beta 1

14.0.0

Nextcloud Server 14.0.0 Beta 2

14.0.0

Nextcloud Server 14.0.0 Beta 3

14.0.0

Nextcloud Server 14.0.0 Beta 4

14.0.0

Nextcloud Server 14.0.0 Release Candidate 1

14.0.0

Nextcloud Server 14.0.0 Release Candidate 2

14.0.0

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