SB2018030643 - Fedora 27 update for zsh
Published: March 6, 2018 Updated: April 24, 2025
Security Bulletin ID
SB2018030643
CSH Severity
Low
Patch available
YES
Number of vulnerabilities
2
Exploitation vector
Local access
Highest impact
Partial DoS
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Improper input validation (CVE-ID: CVE-2018-7549)
CWE-ID: CWE-20 - Improper input validation
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
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)
CWE-ID: CWE-476 - NULL Pointer Dereference
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
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.
Remediation
Install update from vendor's website.