Buffer overflow in MongoDB
CVE-2021-32040
It may be possible to have an extremely long aggregation pipeline in conjunction with a specific stage/operator and cause a stack overflow due to the size of the stack frames used by that stage. If an attacker could cause such an aggregation to occur, they could maliciously crash MongoDB in a DoS attack. This vulnerability affects MongoDB Server v4.4 versions prior to and including 4.4.28, MongoDB Server v5.0 versions prior to 5.0.4 and MongoDB Server v4.2 versions prior to 4.2.16. Workaround: >= v4.2.16 users and all v4.4 users can add the --setParameter internalPipelineLengthLimit=50 instead of the default 1000 to mongod at startup to prevent a crash.
Vulnerability class: Buffer Overflow
EPSS: 0.020 (78.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H.
Affected products
- Mongodb
- Mongodb Inc. Server — versions 5.0, 4.4, 4.2
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cna@mongodb.com (Patch, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- cna@mongodb.com (Patch, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- cna@mongodb.com (Patch, x_refsource_MISC, Issue Tracking, Vendor Advisory)
- cna@mongodb.com (x_refsource_CONFIRM, Third Party Advisory)
Frequently asked questions
- What is CVE-2021-32040?
- CVE-2021-32040 is a medium-severity vulnerability in MongoDB, classified under Stack-based Buffer Overflow. CVSS score: 6.5/10. Published 2022-04-12.
- How severe is CVE-2021-32040?
- Medium severity. CVSS v3 base score is 6.5 out of 10.
- Is CVE-2021-32040 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.