CVE-2020-1736
Description
A flaw was found in Ansible Engine when a file is moved using atomic_move primitive as the file mode cannot be specified. This sets the destination files world-readable if the destination file does not exist and if the file exists, the file could be changed to have less restrictive permissions before the move. This issue affects only the newly created files and not existing ones. If the file already exists at the final destination, those permissions are retained. This could lead to the disclosure of sensitive data.
Statement
Ansible Engine 2.8.14 and 2.9.12 as well as previous versions and all 2.7.x versions are affected.
Ansible Tower 3.6.5 and 3.7.2 as well as previous versions are affected.
In Red Hat OpenStack Platform, because the flaw has a lower impact, ansible is not directly customer exposed, and the fix would require a substantial amount of development, no update will be provided at this time for the RHOSP ansible package.
Mitigation
This issue can be mitigated by specifying the "mode" on the task. That just leaves a race condition in place where newly created files that specify a mode in the task briefly go from 666 - umask to the final mode. An alternative workaround if many new files are created and to avoid setting a specific mode for each file would be to set the "mode" to "preserve" value. That will maintain the permissions of the source file on the controller in the final file on the managed host.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 2.2 | 3.3 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | High | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | Required | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | Low | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:L/I:N/A:N
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Application Data; Read Files or Directories
An attacker may be able to read sensitive information from the associated resource, such as credentials or configuration information stored in a file.
Access Control
Technical Impact: Gain Privileges or Assume Identity
An attacker may be able to modify critical properties of the associated resource to gain privileges, such as replacing a world-writable executable with a Trojan horse.
Integrity,Other
Technical Impact: Modify Application Data; Other
An attacker may be able to destroy or corrupt critical data in the associated resource, such as deletion of records from a database.
Acknowledgements
Red Hat would like to thank Damien Aumaitre (Quarkslab) and Nicolas Surbayrole (Quarkslab) for reporting this issue.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
