Vulnerability management

Zero-Day Vulnerability in Windows (CVE-2024-49138): PoC Released, Exploited in the Wild

Summary

OEM

Microsoft

Severity

Critical

CVSS Score

7.8

CVE

CVE-2024-49138

Exploited in Wild

Yes

Patch/Remediation Available

Yes

Advisory Version

1.0

Publicly POC Available

Yes


Overview

The vulnerability CVE-2024-49138, affecting the Windows Common Log File System (CLFS) driver, enables attackers to gain SYSTEM privileges via a heap-based buffer overflow. Security researcher MrAle_98 published a proof-of-concept (PoC) exploit, increasing its potential misuse.

Vulnerability Name

CVE ID

Product Affected

Severity

CLFS Privilege Escalation

CVE-2024-49138

Microsoft Windows

High

Technical Summary

CVE-2024-49138 is a heap-based buffer overflow vulnerability in the Windows Common Log File System (CLFS) driver, allowing attackers to escalate privileges to SYSTEM level. It affects a wide range of Windows systems, including the latest versions, such as Windows 11 23H2. Initially discovered by CrowdStrike’s Advanced Research Team, Microsoft confirmed active exploitation prior to its December 2024 patch release. Security researcher MrAle_98 published a proof-of-concept exploit on GitHub, increasing the likelihood of threat actor replication and exploitation.

CVE ID

System Affected

Vulnerability Details

Impact

CVE-2024-49138

Windows 10, Windows 11, Windows Server 2008–2025

Heap buffer overflow in CLFS driver enabling SYSTEM access. Exploited in the wild and PoC publicly released.

Enables attackers to elevate their privileges to SYSTEM level, granting them complete control over an affected device.

Remediations

  1. Update Systems: Apply Microsoft’s December 2024 patches without delay.
  2. Monitor Systems: Be alert for unusual privilege escalations or indicators of compromise.
  3. Limit Access: Implement robust access controls and harden systems.

Conclusion:

The public release of a proof-of-concept exploit heightens risks, making immediate patching essential. Organizations must prioritize updates, monitor for exploitation, and implement strict access controls.

Race Condition Vulnerability in OpenSSH (CVE-2024-6387): PoC Exploit Released  

Race Condition Vulnerability in OpenSSH (CVE-2024-6387): PoC Exploit Released  

OpenSSH is a suite of networking utilities based on the Secure Shell (SSH) protocol. It is extensively used for secure remote login, remote server management and administration, and file transfers via SCP and SFTP. OpenSSH server process ‘sshd’ is affected by a signal handler race condition allowing unauthenticated remote code execution with root privileges on glibc-based Linux systems.

Summary 

Application  OpenSSH 
Severity  High 
CVSS  8.1 
CVEs  CVE-2024-6387 
Exploited in Wild  Yes 
Patch/Remediation Available  Yes 
Advisory Version  1.0 

Overview 

CVE-2024-6387, a high-severity vulnerability in OpenSSH’s server (sshd), has been identified and is currently being exploited in the wild. Known as “regreSSHion,” this flaw involves a sophisticated race condition during the authentication phase, allowing unauthenticated remote attackers to execute arbitrary code with root privileges.

A proof-of-concept (PoC) exploit for this critical vulnerability has been released, further raising concerns. 

The vulnerability affects millions of OpenSSH servers globally, with older versions particularly at risk. Rated with a CVSS score of 8.1, the flaw poses a significant security threat. Over 14 million OpenSSH server instances exposed to the Internet have been identified as potentially vulnerable, with around 700,000 instances facing external internet threats. 

Vulnerability Name  CVE ID  Product Affected  Severity  Fixed Version 
Race Condition vulnerability    CVE-2024-6387   OpenSSH (8.5p1–9.8p1)   High   OpenSSH 9.8p2 or later 

Technical Summary 

CVE-2024-6387, also known as “regreSSHion,” is a critical vulnerability in OpenSSH’s server (sshd) caused by a signal handler race condition. This issue arises when the SIGALRM handler, triggered during a failed login attempt exceeding LoginGraceTime, invokes non-async-signal-safe functions like syslog(). The Vulnerability allows unauthenticated remote attackers to execute arbitrary code with root privileges, primarily affecting glibc-based Linux systems.

Exploitation is technically complex but feasible and has been demonstrated in controlled environments on 32-bit systems. OpenBSD systems are unaffected due to their different signal-handling mechanisms. 

CVE ID  System Affected  Vulnerability Details  Impact 
CVE-2024-6387  OpenSSH v8.5p1 through 9.8p1 on glibc-based Linux systems  Signal handler race condition in sshd’s SIGALRM, triggered during login timeout (LoginGraceTime).  Remote Code Execution (Root Privileges) 

Impact:

This Vulnerability if exploited could lead to complete system takeover.

Remediation

  • Immediate Patch: Upgrade OpenSSH to version 9.8p2 or later, which resolves the issue. 
  • Access Restrictions: Implement firewall rules or TCP wrappers to limit SSH access to trusted IP ranges. 
  • Monitor Activity: Use intrusion detection systems (IDS) to analyze logs for unusual activity, failed login attempts, or exploitation patterns. 

Indicators of Compromise (IOCs): 

IP Address / Hostname  File Hash 
209.141.53[.]247  0df799f05c6d97e2b7d4b26c8e7246f7 
108.174.58[.]28  11cc5f00b466d4f9be4e0a46f2eb51ae 
195.85.205[.]47  1f452448cea986aedc88ba50d48691f7 
62.72.191[.]203  207eb58423234306edaecb3ec89935d8 
botbot.ddosvps.cc   

Below are some IOCs associated with the threat. For a complete list of IOCs, refer to the AlienVault Pulse for CVE-2024-6387 

Conclusion: 

The public release of a PoC exploit for CVE-2024-6387 marks a critical moment for organizations relying on OpenSSH. While exploitation requires significant effort, the potential impact of a successful attack—complete system compromise and privilege escalation—is severe.

Swift patching and the adoption of layered security measures are imperative to mitigate the risks. 

Organizations must act promptly to safeguard their systems and monitor for signs of active exploitation. By staying informed and proactive, businesses can minimize the potential fallout from this serious vulnerability. 

References: 

  • https://nvd.nist.gov/vuln/detail/cve-2024-6387 
  • https://www.yorku.ca/uit/2025/01/openssh-remote-code-execution-regresshion-cve-2024-6387/

Critical Apache Tomcat Vulnerabilities Allow RCE & DoS

Summary

OEMApache
SeverityCritical
CVSS9.8
CVEsCVE-2024-50379, CVE-2024-54677
Exploited in WildYes
Patch/Remediation AvailableYes
Advisory Version1.0

Overview

Recent vulnerabilities in Apache Tomcat, identified as CVE-2024-50379 and CVE-2024-54677, present significant security threats, including remote code execution (RCE) and denial-of-service (DoS) risks. CVE-2024-50379 exploits a race condition during JSP compilation on case-insensitive file systems, enabling attackers to run arbitrary code. CVE-2024-54677 takes advantage of unlimited file uploads in example applications to trigger resource exhaustion.

Vulnerability NameCVE IDProduct AffectedSeverityAffected Version
Race Condition Vulnerability CVE-2024-50379ApacheCriticalApache Tomcat 11.0.0-M1 to 11.0.1 Apache Tomcat 10.1.0-M1 to 10.1.33 Apache Tomcat 9.0.0.M1 to 9.0.97
Uncontrolled Resource Consumption Vulnerability CVE-2024-54677ApacheMediumApache Tomcat 11.0.0-M1 to 11.0.1 Apache Tomcat 10.1.0-M1 to 10.1.33 Apache Tomcat 9.0.0.M1 to 9.0.97

Technical Summary

CVE IDSystem AffectedVulnerability DetailsImpact
CVE-2024-50379Apache TomcatA race condition during JSP compilation in Apache Tomcat allows attackers to upload malicious JSP files, leading to remote code execution. This occurs when the default servlet is configured with write permissions on a case-insensitive file system.    Remote Code Execution
CVE-2024-54677Apache TomcatThe examples web application in Apache Tomcat does not limit the size of uploaded data, enabling attackers to cause an OutOfMemoryError by uploading excessive amounts of data, leading to a denial of service.    Denial of Service

Remediation:

  • Upgrade Apache Tomcat to the latest fixed versions:
    • Apache Tomcat 11.0.2 or latest
    • Apache Tomcat 10.1.34 or latest
    • Apache Tomcat 9.0.98 or latest

Recommendations:

  • Configuration Hardening:
    • Restrict write permissions for the default servlet to prevent unauthorized JSP file uploads.
    • Remove or disable example applications to reduce exposure to potential attacks.
  • Monitor and Audit:
    • Regularly review server logs for signs of exploitation attempts.
    • Apply a robust file upload policy to limit sizes and validate content.
  • Regularly update all your software’s to address security vulnerabilities 

References:

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