01 Record
CVE-2021-36088
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_parser_do).
CriticalPUBLISHEDCNA: mitre
CNA base score9.8 CVSS v3.xCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
02 Description
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_parser_do).
03 Exploitation and scoring
- Exploitation
- Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
- SSVC decision
- ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
- AutomatableyesAn attacker can reliably automate reconnaissance through exploitation, so this scales.
- Technical ImpacttotalSuccessful exploitation gives total control of the vulnerable component.
- EPSS probability
- 2.38% probability of exploitation activity in the next 30 days.
- EPSS percentile
- Equal to or higher than the score of 83.4% of scored records. A rank, not a probability.
- NVD base score
- 9.8 (CVSS v3.x), scored by the NVD independently of the CNA.
- NVD CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- NVD analysis status
- Modified. NVD last modified this record on 2026-06-17.
- Red Hat severity
- No Red Hat rating. Red Hat rates the CVEs that affect its products.
Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.
04 Metadata
- Published
- 2021-07-01 02:50Z5 YR AGO
- Last updated
- 2024-08-04 00:47Z2 YR AGO
- Reserved
- 2021-07-01
- Assigning CNA
- mitre
- Record state
- PUBLISHED
- Severity
- Critical (CVSS 9.8)
- CNA CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weaknesses
- CWE-415Double FreeVariant
- Data version
- 5.1
- Document digest
- ab5e25841650c1c8fb95118bcacb001a88c85c854095b3763066099e16b1ccca
05 Affected products
VendorProductVersionsPlatforms
06 References
- bugs.chromium.orghttps://bugs.chromium.org/p/oss-fuzz/issues/detail?id=33750
- github.comhttps://github.com/google/oss-fuzz-vulns/blob/main/vulns/fluent-bit/OSV-2021-702.yaml
- github.comhttps://github.com/fluent/fluent-bit/commit/22346a74c07ceb90296be872be2d53eb92252a54
- github.comhttps://github.com/fluent/fluent-bit/pull/3453