CVE-1999-0433: Medium severity Xfree86 Project X11r6 vulnerability
XFree86 startx command is vulnerable to a symlink attack, allowing local users to create files in restricted directories, possibly allowing them to gain privileges or cause a denial of service.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Remove
Remove
XFree86/startxfrom your environment.Uninstall or remove the XFree86 'startx' binary from affected systems until a vendor-supplied patch is available to eliminate the vulnerable program.
- Configuration
Remove the setuid bit (or otherwise restrict execute permissions) on the startx binary so unprivileged users cannot execute it with elevated privileges.
XFree86 startx setuid bit / execute permissions = remove setuid / restrict execution to trusted users - Compensating control
Restrict which local accounts can start X sessions and access directories that could be abused by the vulnerability (use filesystem permissions, group restrictions, PAM/account controls, or local policy to prevent untrusted users from running startx).
- Operational
Audit restricted directories for unexpected or unauthorized files and clean up any artifacts; investigate for potential privilege escalation and rotate any credentials or keys if compromise is suspected.
Event History
Frequently Asked Questions
What is the severity of CVE-1999-0433?
CVE-1999-0433 is considered a moderate severity vulnerability due to the potential for local privilege escalation.
How do I fix CVE-1999-0433?
To fix CVE-1999-0433, it is recommended to update XFree86 to a version that does not exhibit the symlink vulnerability.
Which software is affected by CVE-1999-0433?
CVE-1999-0433 affects several versions of XFree86 and various distributions of Linux including NetBSD and Red Hat.
Can CVE-1999-0433 lead to system compromise?
Yes, CVE-1999-0433 can allow local users to create files in restricted directories, potentially leading to system compromise or denial of service.
Is there a workaround for CVE-1999-0433 if I cannot update?
A potential workaround for CVE-1999-0433 includes restricting user permissions on directories that may be susceptible to symlink attacks.