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Fluent Bit CVE-2024-23722

HIGH
NULL Pointer Dereference (CWE-476)
2024-03-26 cve@mitre.org
7.5
CVSS 3.1 · Vendor: mitre
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Vulnerability Assessment

Weakness
CWE
OWASP Top 10:2025
A10:2025 - Mishandling of Exceptional Conditions
ASVS 5.0
V16 - Security Logging and Error Handling Null pointer safety, defensive checks
MITRE ATT&CK

1 technique across 1 tactic: Impact

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

Impact

CVSS score of 7.5 (HIGH). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available.

Exploit ScenarioDerived

A remote attacker could crash the application by dereferencing a null pointer by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).
Patch available 0.9% exploitation probability (EPSS)

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AnalysisAI

In Fluent Bit 2.1.8 through 2.2.1, a NULL pointer dereference can be caused via an invalid HTTP payload with the content type of x-www-form-urlencoded. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Check pointers before dereferencing. Use static analysis tools to detect null pointer paths.

Affects your stack

Find out whether the stacks and servers you run are on an affected version.

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

Technical ContextAI · show details

This vulnerability is classified as NULL Pointer Dereference (CWE-476), which allows attackers to crash the application by dereferencing a null pointer. In Fluent Bit 2.1.8 through 2.2.1, a NULL pointer dereference can be caused via an invalid HTTP payload with the content type of x-www-form-urlencoded. It crashes and does not restart. This could result in logs not being delivered properly. Affected products include: Treasuredata Fluent Bit. Version information: through 2.2.1.

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  • Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

Vendor (mitre) PRIMARY 7.5 HIGH
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Primary rating from Vendor (mitre) · only source for this CVE.

CVSS VectorVendor: mitre

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

DescriptionCVE.org

In Fluent Bit 2.1.8 through 2.2.1, a NULL pointer dereference can be caused via an invalid HTTP payload with the content type of x-www-form-urlencoded. It crashes and does not restart. This could result in logs not being delivered properly.

Threat Intelligence Overview

EPSS Score
0.9%
Top 43% exploitable
Exploit
POC
Public exploit code exists
Data Quality
3 sources
Confidence: Low

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue
Severity HIGH
CISA KEV No
Public POC Yes
EPSS 0.9%
Patch available Yes
Active threat No
Deciding rule
HIGH severity (CVSS 7.0-8.9)
What every action level means
Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.
Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.
This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.
This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.
Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision· derived
Scheduled
Exploitation· derived
Poc
System Exposure· derived
Open
Automatable· derived
Yes
Human Impact· derived
Medium

Priority Score

59
Low Medium High Critical
KEV: 0
EPSS: +1
CVSS: +38
PoC: +20
Weaponized: 0
Threat intel: 0
Gov advisory: 0

Attack Technique

A null pointer dereference occurs when a program attempts to access memory through a pointer that has been set to NULL (address 0x0).

Denial of Service attacks render applications or systems unavailable by overwhelming resources or triggering failure conditions.

Affected Products (CPE)CVE.org

cpe:2.3:a:treasuredata:fluent_bit:*:*:*:*:*:*:*:*
CVE-2024-4323 CRITICAL POC
9.8 May 20

A memory corruption vulnerability in Fluent Bit versions 2.0.7 thru 3.0.3. Rated critical severity (CVSS 9.8), this vuln

CVE-2021-36088 CRITICAL POC
9.8 Jul 01

Fluent Bit (aka fluent-bit) 1.7.0 through 1.7.4 has a double free in flb_free (called from flb_parser_json_do and flb_pa

CVE-2024-50609 HIGH POC
7.5 Feb 18

An issue was discovered in Fluent Bit 3.1.9. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable,

CVE-2024-50608 HIGH POC
7.5 Feb 18

An issue was discovered in Fluent Bit 3.1.9. Rated high severity (CVSS 7.5), this vulnerability is remotely exploitable,

CVE-2024-26455 HIGH POC
7.5 Feb 26

fluent-bit 2.2.2 contains a Use-After-Free vulnerability in /fluent-bit/plugins/custom_calyptia/calyptia.c. Rated high s

CVE-2021-27186 HIGH POC
7.5 Feb 10

Fluent Bit 1.6.10 has a NULL pointer dereference when an flb_malloc return value is not validated by flb_avro.c or http_

CVE-2019-9749 HIGH POC
7.5 Mar 13

An issue was discovered in the MQTT input plugin in Fluent Bit through 1.0.4. Rated high severity (CVSS 7.5), this vulne

CVE-2025-29478 MEDIUM POC
5.5 Apr 07

An issue in fluent-bit v.3.7.2 allows a local attacker to cause a denial of service via the cfl_list_size in cfl_list.h:

CVE-2025-29477 MEDIUM POC
5.5 Apr 04

An issue in fluent-bit v.3.7.2 allows a local attacker to cause a denial of service via the function consume_event. Rate

CVE-2026-61674 CRITICAL
9.2 Sep 21

Stack-based buffer overflow in Fluent Bit's out_forward Secure Forward plugin (versions 0.11.0 through releases prior to

CVE-2025-12969 MEDIUM
6.5 Nov 24

Fluent Bit in_forward input plugin does not properly enforce the security.users authentication mechanism under certain c

CVE-2025-12978 MEDIUM
5.4 Nov 24

Fluent Bit in_http, in_splunk, and in_elasticsearch input plugins contain a flaw in the tag_key validation logic that fa

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