CVE-2024-25678 – This vulnerability in LiteSpeed QUIC (LSQUIC) L... (How to Fix)

Q: What is the severity of CVE-2024-25678?

CVE-2024-25678 has a CVSS score of 9.8 (CRITICAL). This vulnerability in LiteSpeed QUIC (LSQUIC) Library involves mishandled DCID (Destination Connection ID) validation, allowing attackers to potentially bypass security controls or cause denial of service. It affects systems using LSQUIC Library versions before 4.0.4 for QUIC protocol implementations.

📋 TL;DR

This vulnerability in LiteSpeed QUIC (LSQUIC) Library involves mishandled DCID (Destination Connection ID) validation, allowing attackers to potentially bypass security controls or cause denial of service. It affects systems using LSQUIC Library versions before 4.0.4 for QUIC protocol implementations.

💻 Affected Systems

Products:

LiteSpeed QUIC (LSQUIC) Library

Versions: All versions before 4.0.4

Operating Systems: All platforms running LSQUIC

Default Config Vulnerable: ⚠️ Yes

Notes: Affects any application or service using vulnerable LSQUIC library versions

📦 What is this software?

Lsquic by Litespeedtech

View all CVEs affecting Lsquic →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution, complete system compromise, or persistent denial of service affecting all QUIC connections

🟠

Likely Case

Denial of service through connection disruption or resource exhaustion

🟢

If Mitigated

Limited impact with proper network segmentation and monitoring

🌐 Internet-Facing: HIGH

🏢 Internal Only: MEDIUM

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ⚠️ Yes

Complexity: MEDIUM

Exploitation requires understanding of QUIC protocol and DCID handling

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: 4.0.4

Vendor Advisory: https://github.com/litespeedtech/lsquic/releases/tag/v4.0.4

Restart Required: Yes

Instructions:

1. Download LSQUIC v4.0.4 from GitHub releases. 2. Replace existing LSQUIC installation with patched version. 3. Restart all services using LSQUIC library.

🔧 Temporary Workarounds

Disable QUIC/HTTP3

all

Temporarily disable QUIC protocol support to mitigate vulnerability

Configure web server/application to use HTTP/1.1 or HTTP/2 only

🧯 If You Can't Patch

Implement network segmentation to isolate QUIC-enabled services
Deploy WAF/IPS rules to detect abnormal QUIC connection patterns

🔍 How to Verify

Check if Vulnerable:

Check LSQUIC library version in use; if version < 4.0.4, system is vulnerable

Check Version:

Check application documentation for version query method or examine library files

Verify Fix Applied:

Confirm LSQUIC version is 4.0.4 or later after update

📡 Detection & Monitoring

Log Indicators:

Unusual QUIC connection failures
Abnormal DCID patterns in QUIC logs

Network Indicators:

Malformed QUIC packets targeting DCID validation
Spike in QUIC connection resets

SIEM Query:

QUIC AND (error OR failure OR reset) AND DCID

📊 Metadata

CVE ID: CVE-2024-25678

CVSS v3 Score: 9.8 (CRITICAL)

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

CWE: CWE-354

Published: February 9, 2024

Last Updated: June 20, 2025

🔗 References

https://github.com/litespeedtech/lsquic/commit/515f453556c99d27c4dddb5424898dc1a5537708 Patch
https://github.com/litespeedtech/lsquic/releases/tag/v4.0.4 Release Notes
https://www.rfc-editor.org/rfc/rfc9001 Not Applicable
https://github.com/litespeedtech/lsquic/commit/515f453556c99d27c4dddb5424898dc1a5537708 Patch
https://github.com/litespeedtech/lsquic/releases/tag/v4.0.4 Release Notes
https://www.rfc-editor.org/rfc/rfc9001 Not Applicable

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