HOMEVULNERABILITIESCVE-2021-46878
HIGH

CVE-2021-46878

CWE-843Published: April 11, 2023· Updated: Jun 17, 2026

7.8
CVSS v3.1

Official Description

An issue was discovered in Treasure Data Fluent Bit 1.7.1, erroneous parsing in flb_pack_msgpack_to_json_format leads to type confusion bug that interprets whatever is on the stack as msgpack maps and arrays, leading to use-after-free. This can be used by an attacker to craft a specially craft file and trick the victim opening it using the affect software, triggering use-after-free and execute arbitrary code on the target system.

NVD Source

Technical Analysis

CVE-2021-46878 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation does not require any privileges, though user interaction (Required) is needed, which slightly reduces the risk of mass automated attacks.

A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 7.8.

CVSS v3.1 Vector Breakdown

Exploitability
Attack VectorLocal
Attack ComplexityLow
Privileges Req.None
User InteractionRequired
ScopeUnchanged
Impact
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

Affected Vendors & Products

treasuredata1 product(s)
fluent bit
Source: NVD CPE · 1 total CPE entries

Exploit & PoC Resources

NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
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Official Patches & Advisories

PATCHhttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27742
PATCHhttps://github.com/fluent/fluent-bit/pull/3115
PATCHhttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27742
PATCHhttps://github.com/fluent/fluent-bit/pull/3115

All References (4)

→
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27742Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://github.com/fluent/fluent-bit/pull/3115Patch
→
https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=27742Exploit · Issue Tracking · Patch · Third Party Advisory
→
https://github.com/fluent/fluent-bit/pull/3115Patch

Quick Facts

CVE IDCVE-2021-46878
CVSS Score7.8 / 10
SeverityHIGH
WeaknessCWE-843
CISA KEVNo
Affected1 vendor(s)
PublishedApr 11, 2023

Related CVEs (CWE-843)

CVE-2010-2299
10.0
CVE-2021-33970
10.0
CVE-2019-7970
9.8
CVE-2019-14537
9.8
CVE-2019-2130
9.8
CVE-2019-7969
9.8

Recommended Actions

  • →Apply vendor patches immediately
  • →Monitor CVE-2021-46878 in threat intel feeds
  • →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.
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