Canonical ubuntu-pro-client Credentials Validation /usr/lib/apt/apt-helper download-file missing encryption

Summaryinfo

A vulnerability was found in Canonical ubuntu-pro-client. It has been rated as problematic. This affects the function download-file of the file /usr/lib/apt/apt-helper of the component Credentials Validation. This manipulation causes missing encryption. The identification of this vulnerability is CVE-2026-9494. The attack can only be executed locally. There is no exploit available.

Detailsinfo

A vulnerability was found in Canonical ubuntu-pro-client (version unknown). It has been declared as problematic. Affected by this vulnerability is the function download-file of the file /usr/lib/apt/apt-helper of the component Credentials Validation. The manipulation with an unknown input leads to a missing encryption vulnerability. The CWE definition for the vulnerability is CWE-311. The product does not encrypt sensitive or critical information before storage or transmission. As an impact it is known to affect confidentiality. The summary by CVE is:

An information disclosure vulnerability exists in Canonical ubuntu-pro-client (formerly ubuntu-advantage-tools). The client validates Ubuntu Pro APT credentials by executing /usr/lib/apt/apt-helper using the download-file command. During this process, the secret bearer token is embedded directly in the cleartext URL component passed via the command-line arguments (argv), resulting in a URL format such as https://bearer:<token>@esm.ubuntu.com/.../. On systems utilizing a default-mounted /proc file system where process-hiding mitigations (such as hidepid) are disabled, an unprivileged local attacker can monitor system processes and read the sensitive bearer token directly from /proc/cmdline while the helper process is actively running. This leaked token can subsequently be used to gain unauthorized access to the victim's Ubuntu Pro or Expanded Security Maintenance (ESM) repositories.

It is possible to read the advisory at ubuntu.com. This vulnerability is known as CVE-2026-9494 since 05/25/2026. The exploitation appears to be difficult. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1600 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Vendor

• Canonical

Name

• ubuntu-pro-client

License

• open-source

CPE 2.3info

• 🔒

CPE 2.2info

• 🔒

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