Security readout for executives and security teams
Plain-English summary
CVE-2021-36686 is a medium-severity cross-site scripting issue reported in yapi 1.9.1. An authenticated user could place script content through the interface API edit page, potentially affecting another user who views it. Business risk depends on whether yapi is used internally and who can edit or view API interfaces.
Executive priority
Treat this as a moderate internal application risk. Prioritize if yapi is internet-accessible, broadly editable, or used by privileged engineering teams. Otherwise handle through normal vulnerability management.
Technical view
The CVE describes CWE-79 in yapi 1.9.1 on the /interface/api edit page. CVSS 3.1 is 5.4: network reachable, low complexity, low privileges required, user interaction required, changed scope, low confidentiality and integrity impact, no availability impact. Affected-product metadata is incomplete in the CVE bundle.
Likely exposure
Exposure is most likely in organizations running yapi 1.9.1 or similar unverified deployments, especially where multiple users can edit and view API interface records.
Exploitation context
The bundle does not show CISA KEV listing or cited evidence of active exploitation. Exploitation requires privileges and user interaction, reducing urgency but still relevant for shared internal developer platforms.
Researcher notes
The public bundle identifies the vulnerable page and CVSS vector but does not provide a named patch, complete CPE data, or exploitation evidence. Validate against the linked GitHub issues and project releases before asserting fixed versions.
Mitigation direction
- Check YMFE/yapi guidance and release history for a fixed version.
- Upgrade or apply project-provided fixes when identified by the maintainer.
- Restrict interface editing to trusted authenticated users only.
- Reduce external access to yapi instances where possible.
- Review stored interface content for unexpected script-like entries.
Validation and detection
- Inventory yapi deployments and confirm exact versions.
- Flag yapi 1.9.1 and any unverified nearby versions for review.
- Review access controls for the /interface/api edit workflow.
- Check logs for unusual interface editing activity.
- Use non-destructive staging tests to confirm output encoding behavior.
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-79: User-session and phishing behavior lookup
Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. 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 lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-36686 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
- 5.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
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:R/S:C/C:L/I:L/A:N2.32.7Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
5.4MediumVector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/YMFE/yapi/issues/2190CVE reference
- https://github.com/YMFE/yapi/issues/2240CVE reference
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.
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.