Security readout for executives and security teams
Plain-English summary
CVE-2018-20803 is a MongoDB Server denial-of-service flaw. A logged-in user who can run database queries may issue a specially crafted query that causes an infinite loop, consuming availability by holding locks. It does not indicate data theft or modification.
Executive priority
Prioritize remediation for business-critical MongoDB deployments and shared database clusters. The issue is not a confidentiality breach, but it can disrupt availability if an authorized account is misused or compromised.
Technical view
The issue is CWE-835 in MongoDB aggregation expression mathematics processing. A network-accessible, low-privileged authenticated query can trigger indefinite looping while retaining locks, causing high availability impact. Affected branches are 4.0 before 4.0.5, 3.6 before 3.6.10, and 3.4 before 3.4.19.
Likely exposure
Exposure is most likely in environments still running MongoDB Server 3.4, 3.6, or 4.0 below the fixed versions, especially where many application or user accounts can run database queries.
Exploitation context
The CVE record does not report active exploitation, and CISA KEV status is false in the provided bundle. Exploitation requires valid query authorization, so risk depends on account access, service exposure, and workload criticality.
Researcher notes
The public data identifies affected versions, CVSS 6.5, CWE-835, and a denial-of-service condition in aggregation expression math processing. The bundle does not include exploit details, proof-of-concept status, or broader product impact.
Mitigation direction
- Upgrade affected MongoDB Server branches to 4.0.5, 3.6.10, 3.4.19, or later supported releases.
- Restrict database query privileges to trusted accounts until upgraded.
- Monitor for long-running aggregation queries and lock contention.
- Review MongoDB SERVER-38070 and vendor guidance for deployment-specific instructions.
Validation and detection
- Inventory MongoDB Server versions and compare them with the affected version ranges.
- Confirm production and replica set members are on fixed or later supported versions.
- Review accounts authorized to run database queries for least privilege.
- Check operational monitoring for unusual long-running aggregation activity or lock contention.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-835: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupDatabase behavior lookup
The CVE wording references database injection or access, so collection and exfiltration review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2018-20803 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Medium
- CVSS
- 6.5 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H2.83.6Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
6.5MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://jira.mongodb.org/browse/SERVER-38070CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Loop with Unreachable Exit Condition ('Infinite Loop')
Loop with Unreachable Exit Condition ('Infinite Loop') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.