CVE-2012-3409 – CVE-2012-3409 is a privilege escalation vulnera... (How to Fix)

Q: What is the severity of CVE-2012-3409?

CVE-2012-3409 has a CVSS score of 7.8 (HIGH). CVE-2012-3409 is a privilege escalation vulnerability in ecryptfs-utils where the setuid helper program fails to restrict mounting filesystems with nosuid and nodev options. This allows local attackers to mount arbitrary filesystems and potentially gain root privileges. Systems using ecryptfs-utils with the vulnerable setuid helper are affected.

📋 TL;DR

CVE-2012-3409 is a privilege escalation vulnerability in ecryptfs-utils where the setuid helper program fails to restrict mounting filesystems with nosuid and nodev options. This allows local attackers to mount arbitrary filesystems and potentially gain root privileges. Systems using ecryptfs-utils with the vulnerable setuid helper are affected.

💻 Affected Systems

Products:

ecryptfs-utils

Versions: Versions prior to 89-1

Operating Systems: Linux distributions using ecryptfs-utils

Default Config Vulnerable: ⚠️ Yes

Notes: Systems with ecryptfs-utils installed and the setuid helper enabled are vulnerable. The vulnerability is in the mount.ecryptfs_private helper.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Local attacker gains full root privileges on the system, leading to complete system compromise.

🟠

Likely Case

Local user with limited privileges escalates to root by mounting specially crafted filesystems.

🟢

If Mitigated

Attack fails due to proper filesystem mount restrictions or lack of local access.

🌐 Internet-Facing: LOW - This is a local privilege escalation requiring existing access to the system.

🏢 Internal Only: MEDIUM - Internal users with shell access could exploit this to gain root privileges.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ✅ No

Complexity: LOW

Exploitation requires local access to the system. Proof-of-concept code was published in the original advisory.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: ecryptfs-utils 89-1 and later

Vendor Advisory: https://access.redhat.com/security/cve/cve-2012-3409

Restart Required: No

Instructions:

1. Update ecryptfs-utils package to version 89-1 or later using your distribution's package manager. 2. For Red Hat/CentOS: yum update ecryptfs-utils. 3. For Debian/Ubuntu: apt-get update && apt-get install ecryptfs-utils.

🔧 Temporary Workarounds

Remove setuid bit from mount.ecryptfs_private

linux

Temporarily remove the setuid permission from the vulnerable helper program

chmod u-s /sbin/mount.ecryptfs_private

Disable ecryptfs mounting

linux

Prevent use of ecryptfs mounting capabilities

chmod 0 /sbin/mount.ecryptfs_private

🧯 If You Can't Patch

Restrict local user access to systems with vulnerable ecryptfs-utils
Implement strict filesystem mount policies and monitor for unauthorized mount attempts

🔍 How to Verify

Check if Vulnerable:

Check ecryptfs-utils version: rpm -q ecryptfs-utils or dpkg -l ecryptfs-utils. If version is earlier than 89-1, system is vulnerable.

Check Version:

rpm -q ecryptfs-utils 2>/dev/null || dpkg -l ecryptfs-utils 2>/dev/null | grep ^ii

Verify Fix Applied:

Verify ecryptfs-utils version is 89-1 or later and check that /sbin/mount.ecryptfs_private has proper mount restrictions.

📡 Detection & Monitoring

Log Indicators:

Unusual mount operations in system logs
Failed or successful mount.ecryptfs_private executions

Network Indicators:

None - this is a local attack

SIEM Query:

process.name="mount.ecryptfs_private" AND user.name!="root"

📊 Metadata

CVE ID: CVE-2012-3409

CVSS v3 Score: 7.8 (HIGH)

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-20

Published: December 20, 2019

Last Updated: November 21, 2024

🔗 References

http://www.openwall.com/lists/oss-security/2012/07/11/23 Mailing List,Third Party Advisory
http://www.openwall.com/lists/oss-security/2012/07/12/1 Mailing List,Third Party Advisory
http://www.openwall.com/lists/oss-security/2012/07/13/5 Mailing List,Third Party Advisory
https://access.redhat.com/security/cve/cve-2012-3409 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2012-3409 Issue Tracking,Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2012-3409 Third Party Advisory
http://www.openwall.com/lists/oss-security/2012/07/11/23 Mailing List,Third Party Advisory
http://www.openwall.com/lists/oss-security/2012/07/12/1 Mailing List,Third Party Advisory
http://www.openwall.com/lists/oss-security/2012/07/13/5 Mailing List,Third Party Advisory
https://access.redhat.com/security/cve/cve-2012-3409 Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2012-3409 Issue Tracking,Third Party Advisory
https://security-tracker.debian.org/tracker/CVE-2012-3409 Third Party Advisory

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🔗 Related Vulnerabilities

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