CVE-2019-19926 – This CVE describes a NULL pointer dereference v... (How to Fix)

Q: What is the severity of CVE-2019-19926?

CVE-2019-19926 has a CVSS score of 7.5 (HIGH). This CVE describes a NULL pointer dereference vulnerability in SQLite's multiSelect function that can cause denial of service or potentially allow arbitrary code execution. The vulnerability affects SQLite 3.30.1 and exists due to incomplete fixes for CVE-2019-19880. Applications using vulnerable SQLite versions for database operations are affected.

📋 TL;DR

This CVE describes a NULL pointer dereference vulnerability in SQLite's multiSelect function that can cause denial of service or potentially allow arbitrary code execution. The vulnerability affects SQLite 3.30.1 and exists due to incomplete fixes for CVE-2019-19880. Applications using vulnerable SQLite versions for database operations are affected.

💻 Affected Systems

Products:

SQLite
Applications embedding SQLite
Operating systems with SQLite packages

Versions: SQLite 3.30.1 specifically (due to incomplete fix for CVE-2019-19880)

Operating Systems: All platforms running vulnerable SQLite versions

Default Config Vulnerable: ⚠️ Yes

Notes: The vulnerability specifically affects the multiSelect function when processing window functions with certain error conditions.

📦 What is this software?

⚠️ Risk & Real-World Impact

🔴

Worst Case

Remote code execution leading to complete system compromise if combined with other vulnerabilities or memory corruption techniques.

🟠

Likely Case

Application crash or denial of service when processing malicious SQL queries containing window functions.

🟢

If Mitigated

Limited to application instability if proper input validation and error handling are implemented.

🌐 Internet-Facing: MEDIUM - Web applications using SQLite with user-controlled queries could be vulnerable to DoS attacks.

🏢 Internal Only: LOW - Requires specific SQL query patterns to trigger, limiting exposure in controlled environments.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Exploitation requires ability to execute SQL queries against vulnerable SQLite instances, typically through application interfaces.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: SQLite 3.31.0 and later

Vendor Advisory: https://www.sqlite.org/releaselog/3_31_0.html

Restart Required: Yes

Instructions:

1. Download SQLite 3.31.0 or later from sqlite.org. 2. Replace existing SQLite library with patched version. 3. Recompile applications using SQLite if statically linked. 4. Restart affected services.

🔧 Temporary Workarounds

Input validation for SQL queries

all

Implement strict input validation and sanitization for all SQL queries, especially those containing window functions.

Disable window functions if unused

linux

If application doesn't require SQL window functions, consider disabling them through compile-time options.

Compile SQLite with -DSQLITE_OMIT_WINDOWFUNC

🧯 If You Can't Patch

Implement application-level input validation and query sanitization
Deploy WAF rules to block suspicious SQL patterns containing window functions

🔍 How to Verify

Check if Vulnerable:

Check SQLite version: sqlite3 --version should show 3.30.1. Applications using this version are vulnerable.

Check Version:

sqlite3 --version

Verify Fix Applied:

Verify SQLite version is 3.31.0 or higher: sqlite3 --version

📡 Detection & Monitoring

Log Indicators:

Application crashes with segmentation faults
SQL query errors related to window functions
Unexpected process termination during database operations

Network Indicators:

Repeated SQL queries containing window function syntax
Unusual database query patterns

SIEM Query:

source="application.log" AND ("segmentation fault" OR "NULL pointer" OR "window function error")

📊 Metadata

CVE ID: CVE-2019-19926

CVSS v3 Score: 7.5 (HIGH)

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

CWE: CWE-476

Published: December 23, 2019

Last Updated: November 21, 2024

🔗 References

http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00010.html Mailing List,Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00015.html Mailing List,Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00025.html Mailing List,Third Party Advisory
https://access.redhat.com/errata/RHSA-2020:0514 Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf Patch,Third Party Advisory
https://github.com/sqlite/sqlite/commit/8428b3b437569338a9d1e10c4cd8154acbe33089 Patch,Third Party Advisory
https://security.netapp.com/advisory/ntap-20200114-0003/ Third Party Advisory
https://usn.ubuntu.com/4298-1/ Broken Link
https://usn.ubuntu.com/4298-2/ Broken Link
https://www.debian.org/security/2020/dsa-4638 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2020.html Patch,Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00010.html Mailing List,Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00015.html Mailing List,Third Party Advisory
http://lists.opensuse.org/opensuse-security-announce/2020-02/msg00025.html Mailing List,Third Party Advisory
https://access.redhat.com/errata/RHSA-2020:0514 Third Party Advisory
https://cert-portal.siemens.com/productcert/pdf/ssa-389290.pdf Patch,Third Party Advisory
https://github.com/sqlite/sqlite/commit/8428b3b437569338a9d1e10c4cd8154acbe33089 Patch,Third Party Advisory
https://security.netapp.com/advisory/ntap-20200114-0003/ Third Party Advisory
https://usn.ubuntu.com/4298-1/ Broken Link
https://usn.ubuntu.com/4298-2/ Broken Link
https://www.debian.org/security/2020/dsa-4638 Third Party Advisory
https://www.oracle.com/security-alerts/cpuapr2020.html Patch,Third Party Advisory

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