CVE-2015-3246

libuser <0.56.13-8 & 0.60 <0.60-7 - DoS

Title source: llm
STIX 2.1

Exploitation Summary

EIP tracks 3 public exploits for CVE-2015-3246. PoCs published by Metasploit, Qualys Corporation, Qualys, bcoles, including Metasploit module exploits/linux/local/libuser_roothelper_priv_esc.

AI-analyzed exploit summary This Metasploit module exploits a newline injection vulnerability in libuser and userhelper to gain root privileges by inserting a new user with UID=0 in /etc/passwd. It requires the current user's password and targets Red Hat-based systems.

Description

libuser before 0.56.13-8 and 0.60 before 0.60-7, as used in the userhelper program in the usermode package, directly modifies /etc/passwd, which allows local users to cause a denial of service (inconsistent file state) by causing an error during the modification. NOTE: this issue can be combined with CVE-2015-3245 to gain privileges.

Exploits (3)

exploitdb WORKING POC VERIFIED
by Metasploit · rubylocallinux
https://www.exploit-db.com/exploits/44633

This Metasploit module exploits a newline injection vulnerability in libuser and userhelper to gain root privileges by inserting a new user with UID=0 in /etc/passwd. It requires the current user's password and targets Red Hat-based systems.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: libuser and userhelper versions prior to 0.56.13-8 and version 0.60 before 0.60-7
Auth required
Prerequisites: Current user's password · Writable directory · GCC for live compilation (optional)
devstral-2 · analyzed Feb 16, 2026 Full analysis →
exploitdb WRITEUP VERIFIED
by Qualys Corporation · textdoslinux
https://www.exploit-db.com/exploits/37706

This is a detailed advisory from Qualys describing two vulnerabilities (CVE-2015-3245 and CVE-2015-3246) in libuser and userhelper, including exploitation techniques for local privilege escalation via /etc/passwd manipulation. It explains the technical mechanics but does not include executable exploit code.

Classification
Writeup 100%
Attack Type
Lpe
Complexity
Complex
Reliability
Theoretical
Target: libuser (Red Hat-based distributions), userhelper (usermode package)
Auth required
Prerequisites: Local user access · userhelper or chfn linked with libuser
devstral-2 · analyzed Feb 16, 2026 Full analysis →
metasploit WORKING POC GREAT
by Qualys, bcoles · rubypoc
https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/linux/local/libuser_roothelper_priv_esc.rb

This Metasploit module exploits a newline injection vulnerability in libuser and userhelper to gain root privileges by inserting a new user with UID=0 in /etc/passwd. It uses the roothelper.c exploit from Qualys and has been tested on multiple Red Hat-based systems.

Classification
Working Poc 100%
Attack Type
Lpe
Complexity
Moderate
Reliability
Reliable
Target: libuser and userhelper versions prior to 0.56.13-8 and version 0.60 before 0.60-7
Auth required
Prerequisites: gcc for live compilation · current user's password · writable directory · setuid userhelper binary
devstral-2 · analyzed Apr 23, 2026 Full analysis →

References (10)

Core 10
Core References
Third Party Advisory, VDB Entry vdb-entry x_refsource_bid
http://www.securityfocus.com/bid/76022
Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora
http://lists.fedoraproject.org/pipermail/package-announce/2015-July/162947.html
Exploit, Third Party Advisory exploit x_refsource_exploit-db
https://www.exploit-db.com/exploits/44633/
Vendor Advisory x_refsource_confirm
https://access.redhat.com/articles/1537873
Vendor Advisory vendor-advisory x_refsource_redhat
http://rhn.redhat.com/errata/RHSA-2015-1482.html
Mailing List, Third Party Advisory vendor-advisory x_refsource_fedora
http://lists.fedoraproject.org/pipermail/package-announce/2015-August/163044.html
Third Party Advisory, VDB Entry vdb-entry x_refsource_sectrack
http://www.securitytracker.com/id/1033040
Vendor Advisory vendor-advisory x_refsource_redhat
http://rhn.redhat.com/errata/RHSA-2015-1483.html

Scores

EPSS 0.1963
EPSS Percentile 95.6%

Details

CWE
CWE-264
Status published
Products (7)
redhat/libuser 0.60-1
redhat/libuser 0.60-2
redhat/libuser 0.60-3
redhat/libuser 0.60-4
redhat/libuser 0.60-5
redhat/libuser 0.60-6
redhat/libuser < 0.56.13-5
Published Aug 11, 2015
Tracked Since Feb 18, 2026