Security readout for executives and security teams
Plain-English summary
A QuantaStor web/API endpoint can reflect attacker-supplied content into a user's browser. If an authenticated administrator or other user follows a crafted link, browser-stored sensitive data could be exposed. The issue is high severity but requires user interaction, and the provided sources do not show confirmed active exploitation.
Executive priority
Treat this as a high-priority administrative interface risk. It is not currently supported as actively exploited by the provided sources, but public proof-of-concept detail and potential confidentiality impact justify prompt patching and exposure reduction.
Technical view
CVE-2021-42080 is a reflected cross-site scripting issue in OSNEXUS QuantaStor before 6.0.0.355. The CVSS 3.1 score is 7.4, with network attack vector, low complexity, no privileges required, required user interaction, changed scope, and high confidentiality impact. CWE-79 applies.
Likely exposure
Organizations running OSNEXUS QuantaStor versions before 6.0.0.355 are potentially exposed, especially where the web management or API interface is reachable by users who may open attacker-controlled links. The source bundle does not provide complete affected-version metadata beyond the stated pre-6.0.0.355 boundary.
Exploitation context
The CVE source includes a public proof of concept and the references tag exploit material, but this is not evidence of active exploitation. The issue is not listed as CISA KEV in the provided bundle. Successful exploitation depends on convincing a user to visit a crafted URL.
Researcher notes
The record describes reflected XSS with user interaction and confidentiality impact. The affected-version data is incomplete in the structured affected block, while the title and description identify QuantaStor before 6.0.0.355. Avoid asserting broader product impact or active exploitation without additional vendor or KEV evidence.
Mitigation direction
- Upgrade OSNEXUS QuantaStor to version 6.0.0.355 or later where applicable.
- Check OSNEXUS guidance for any product-specific remediation or supported upgrade path.
- Restrict QuantaStor management and API access to trusted administrative networks.
- Review exposure of internet-facing management interfaces and remove unnecessary public access.
- Apply browser and session hardening controls where available for administrative users.
Validation and detection
- Inventory all OSNEXUS QuantaStor instances and record exact software versions.
- Flag any QuantaStor deployment running before 6.0.0.355 for remediation review.
- Confirm whether the QuantaStor web/API interface is reachable from untrusted networks.
- Review web access logs for unusual requests to the affected echo endpoint.
- Validate remediation by confirming the upgraded version and vendor advisory status.
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 lookupCVE-2021-42080 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
- High
- CVSS
- 7.4 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/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:N/UI:R/S:C/C:H/I:N/A:N2.84Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wbsec.nl/osnexusCVE reference · third-party-advisory, technical-description
- https://csirt.divd.nl/DIVD-2021-00020/CVE reference · third-party-advisory
- https://www.osnexus.com/products/software-defined-storageCVE reference · product
- https://csirt.divd.nl/CVE-2021-42080CVE reference · third-party-advisory, technical-description
- https://www.divd.nl/DIVD-2021-00020CVE reference · third-party-advisory, x_transferred
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.