SB2022080122 - VMware Tanzu products update for Cron
Published: August 1, 2022
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 vulnerabilities.
1) Privilege escalation (CVE-ID: CVE-2017-9525)
CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local attacker to gain elevated privileges on the target system.
The weakness exists in Cron due to a flaw in the postinst maintainer script. A local attacker with crontab group privileges can conduct a symlink attack, bypass crontab privilege separation controls and gain root privileges on the target system.
Successful exploitation of the vulnerability results in privilege escalation.
2) Unchecked Return Value (CVE-ID: CVE-2019-9704)
CWE-ID: CWE-252 - Unchecked Return Value
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to the calloc return value is not checked. A local user can create a large crontab file and crash the daemon.
3) Allocation of Resources Without Limits or Throttling (CVE-ID: CVE-2019-9705)
CWE-ID: CWE-770 - Allocation of Resources Without Limits or Throttling
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to Vixie Cron implementation allows unlimited number of lines to be inserted into the crontab file. A local user can create a very large crontab file and consume all available memory on the system.
4) Use-after-free (CVE-ID: CVE-2019-9706)
CWE-ID: CWE-416 - Use After Free
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
The vulnerability allows a local user to perform a denial of service (DoS) attack.
The vulnerability exists due to a use-after-free error in force_rescan_user() function in Vixie Cron. A local user can write specially crafted data to the crontab file, trigger a use-after-free error and crash the daemon.
Remediation
Install update from vendor's website.