CVE-2023-1314 Local Privilege Escalation Vulnerability in cloudflared's Installer

2023-03-2111:01:14

CWE-59

cloudflare

www.cve.org

vulnerability

privilege escalation

cloudflared

windows

msi

exploitation

local access

symbolic links

compromised device

CVSS3

7.5

Attack Vector

LOCAL

Attack Complexity

HIGH

Privileges Required

LOW

User Interaction

NONE

Scope

CHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:N/I:H/A:H

AI Score

7.9

Confidence

High

EPSS

Percentile

5.1%

JSON

A vulnerability has been discovered in cloudflared’s installer (<= 2023.3.0) for Windows 32-bits devices that allows a local attacker with no administrative permissions to escalate their privileges on the affected device. This vulnerability exists because the MSI installer used by cloudflared relied on a world-writable directory.

An attacker with local access to the device (without Administrator rights) can use symbolic links to trick the MSI installer into deleting files in locations that the attacker would otherwise have no access to. By creating a symlink from the world-writable directory to the target file, the attacker can manipulate the MSI installer’s repair functionality to delete the target file during the repair process.

Exploitation of this vulnerability could allow an attacker to delete important system files or replace them with malicious files, potentially leading to the affected device being compromised.

The cloudflared client itself is not affected by this vulnerability, only the installer for 32-bit Windows devices.

CNA Affected

[
  {
    "defaultStatus": "affected",
    "modules": [
      "MSI Installer"
    ],
    "packageName": "cloudflared",
    "platforms": [
      "Windows",
      "32 bit"
    ],
    "product": "cloudflared",
    "repo": "https://github.com/cloudflare/cloudflared",
    "vendor": "Cloudflare",
    "versions": [
      {
        "changes": [
          {
            "at": "2023.3.1",
            "status": "unaffected"
          }
        ],
        "lessThanOrEqual": "<=2023.3.0",
        "status": "affected",
        "version": "0",
        "versionType": "custom"
      }
    ]
  }
]