A flaw was found in the cifs-utils package where the cifs.upcall helper fails to securely drop its root privileges before looking up user information inside a user-controlled environment. A local, low privileged attacker can exploit this by using a crafted request_key payload to trick the root-owned helper into entering a custom environment (namespace) containing a malicious NSS module. This forces the system to load the attacker's controlled NSS Module and configuration, allowing them to execute arbitrary commands as the root user, elevating their privileges and fully compromising the system.
CVSS Details
- CVSS 3.1 Base Score: 7.8
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade cifs-utilsUpgrade pam_cifscredsUpgrade cifs-utils-devel | Jul 15, 2026 | Jul 15, 2026 |
| Amazon_linux_2023 | — | Upgrade pam_cifscreds-debuginfoUpgrade cifs-utils-infoUpgrade cifs-utils-debugsourceUpgrade pam_cifscredsUpgrade cifs-utilsUpgrade cifs-utils-develUpgrade cifs-utils-debuginfo | Jul 8, 2026 | Jun 18, 2026 |
| Redhat Openshift | — | Upgrade rhcos | Aug 10, 2026 | Jun 16, 2026 |
| Redhat_linux | — | Upgrade cifs-utils-debugsourceNo solution existsUpgrade pam_cifscredsUpgrade pam_cifscreds-debuginfoUpgrade cifs-utils-debuginfoUpgrade cifs-utils-develUpgrade cifs-utils | Jul 1, 2026 | Jun 16, 2026 |
| Rocky_linux | — | Upgrade pam_cifscredsUpgrade pam_cifscreds-debuginfoUpgrade cifs-utils-develUpgrade cifs-utils-debugsourceUpgrade cifs-utils-debuginfoUpgrade cifs-utils | Jul 7, 2026 | Jul 5, 2026 |
| Ubuntu | — | Upgrade cifs-utils | Jul 5, 2026 | Jul 2, 2026 |
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