CVE-2019-9937
Description
A vulnerability was found in SQLite due to a NULL pointer dereference in the fts5ChunkIterate function within sqlite3.c, where an attacker could exploit this flaw by creating a specially crafted table, causing the application to crash and resulting in a denial of service condition.
Statement
This vulnerability in the SQLite3 database engine is rated as Low Severity because of its technical nature and severely limited impact, this flaw is a NULL Pointer Dereference (CWE-476) that occurs within the code that handles full text search tables, specifically the fts5 virtual table functionality. The issue is triggered by specific, non-standard actions: interleaving read and write operations within a single database transaction when interacting with an fts5 table. While this condition can be exploited remotely by an unauthenticated user to cause the issue, the inherent mechanism of a NULL pointer dereference almost exclusively leads to a crash of the affected process. Therefore, the attack's outcome is contained to a low impact Denial of Service (DoS), meaning the database service temporarily stops working, but the attacker gains no ability to steal information, tamper with data, or execute unauthorized code on the host system.
This issue did not affect the versions of sqlite as shipped with Red Hat Enterprise Linux 6 and 7 as they did not include support for fts5.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | 7.5 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | Low | High | N/A |
Vector
Red Hat: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
NVD: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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