SB2018030645 - Fedora 26 update for zsh
Published: March 6, 2018 Updated: April 24, 2025
Security Bulletin ID
SB2018030645
Severity
Low
Patch available
YES
Number of vulnerabilities
4
Exploitation vector
Local access
Highest impact
Denial of service
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 4 secuirty vulnerabilities.
1) Improper input validation (CVE-ID: CVE-2018-7549)
The vulnerability allows a local attacker to cause DoS condition on the target system.The weakness exists in the params.c source code file due to improper handling of hash tables. A local attacker can copy an empty hash table with the typeset -p command and cause the service to crash.
2) NULL pointer dereference (CVE-ID: CVE-2018-7548)
The vulnerability allows a local attacker to cause DoS condition on the target system.The weakness exists in the subst.c source code file due to a NULL pointer dereference. A local attacker can implement ${(PA)...} characters on an empty array result, trigger a NULL pointer dereference condition and cause the service to crash.
3) Buffer overflow (CVE-ID: CVE-2017-18206)
The vulnerability allows a local attacker to cause DoS condition on the target system.The weakness exists in the utils.c source code file due to insufficient checks on buffer lengths for symlink expansion. A local attacker can send specially crafted input, trigger memory corruption and cause the service to crash.
4) NULL pointer dereference (CVE-ID: CVE-2017-18205)
The vulnerability allows a local unauthenticated attacker to cause DoS condition on the target system.The weakness exists due to a NULL pointer dereference when processing a cd command while in sh compatibility mode. A local attacker can cause the service to crash.
Remediation
Install update from vendor's website.