USN-5259-3: Cron regression

Severity

Low

Vendor

Canonical Ubuntu

Description

USN-5259-1 and USN-5259-2 fixed vulnerabilities in Cron. Unfortunately that update was incomplete and could introduce a regression. This update fixes the problem. We apologize for the inconvenience. Original advisory details: It was discovered that the postinst maintainer script in Cron unsafely handled file permissions during package install or update operations. An attacker could possibly use this issue to perform a privilege escalation attack. (CVE-2017-9525) Florian Weimer discovered that Cron incorrectly handled certain memory operations during crontab file creation. An attacker could possibly use this issue to cause a denial of service. (CVE-2019-9704) It was discovered that Cron incorrectly handled user input during crontab file creation. An attacker could possibly use this issue to cause a denial of service. (CVE-2019-9705) It was discovered that Cron contained a use-after-free vulnerability in its force_rescan_user function. An attacker could possibly use this issue to cause a denial of service. (CVE-2019-9706) Update Instructions: Run `sudo ua fix USN-5259-3` to fix the vulnerability. The problem can be corrected by updating your system to the following package versions: cron – 3.0pl1-128ubuntu2+esm2 Available with UA Infra or UA Desktop: https://ubuntu.com/advantage

CVEs contained in this USN include: CVE-2017-9525.

Affected Cloud Foundry Products and Versions

Severity is low unless otherwise noted.

• Bionic Stemcells
  • 1.x versions prior to 1.84
  • All other stemcells not listed.
• cflinuxfs3
  • All versions prior to 0.295.0
• CF Deployment
  • All versions prior to 21.0.0, or later versions with Bionic Stemcells prior to 1.84 or Xenial Stemcells prior to 621.241

Mitigation

Users of affected products are strongly encouraged to follow the mitigations below. The Cloud Foundry project recommends upgrading the following releases:

• Bionic Stemcells
  • Upgrade 1.x versions to 1.84 or greater
  • All other stemcells should be upgraded to the latest version available on bosh.io.
• cflinuxfs3
  • Upgrade all versions to 0.295.0 or greater
• CF Deployment
  • Upgrade all versions to 21.0.0 or greater, upgrade Bionic Stemcells to 1.84 or greater, and upgrade Xenial Stemcells to 621.241 or greater

History

2022-07-29: Initial vulnerability report published.