Security readout for executives and security teams
Plain-English summary
Older Nextcloud and ownCloud servers could store unsafe content inside contact-card images and later serve it in a way that may run script in a user's browser. For executives, this is a legacy collaboration-platform risk that could expose user sessions or data if vulnerable versions remain deployed.
Executive priority
Treat as a targeted legacy cleanup item unless affected versions are still internet-accessible or business-critical. Prioritize patching any exposed collaboration server because stored XSS can affect trusted user sessions and sensitive shared data.
Technical view
CVE-2016-9465 is stored cross-site scripting in CardDAV image export. Nextcloud Server before 10.0.1 and ownCloud Server before 9.0.6 and 9.1.2 did not verify vCard image content before download/export, creating a browser-side script execution risk. The weakness is classified as CWE-79.
Likely exposure
Exposure is likely limited to organizations still running the listed legacy Nextcloud or ownCloud versions with CardDAV/contact functionality reachable by users. The source bundle does not identify specific CPEs, CVSS, or internet-wide exposure data.
Exploitation context
The bundle includes a HackerOne report and vendor advisories, but KEV is false and no cited source states active exploitation. Practical abuse would require malicious content being stored in a vCard image and later rendered by a victim's browser.
Researcher notes
Evidence supports the affected-version boundary and XSS class, but not active exploitation or CVSS severity. Review the linked commits and advisories to understand the exact content-validation change before building detection or regression tests.
Mitigation direction
- Upgrade Nextcloud Server to 10.0.1 or later if still on an affected release.
- Upgrade ownCloud Server to 9.0.6, 9.1.2, or later as applicable.
- Review Nextcloud and ownCloud advisories for any environment-specific guidance.
- Retire unsupported legacy instances if they cannot be patched.
- Limit access to contact/CardDAV features until affected systems are upgraded.
Validation and detection
- Inventory all Nextcloud and ownCloud instances and record exact server versions.
- Confirm no production instance is below Nextcloud 10.0.1.
- Confirm no production ownCloud instance is below 9.0.6 or 9.1.2.
- Check whether CardDAV/contact image export is enabled or exposed to users.
- After upgrade, verify contact image export handles content safely in staging.
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-2016-9465 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
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
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 and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://nextcloud.com/security/advisory/?id=nc-sa-2016-008CVE reference · x_refsource_MISC
- https://github.com/owncloud/core/commit/6bf3be3877d9d9fda9c66926fe273fe79cbaf58eCVE reference · x_refsource_MISC
- https://hackerone.com/reports/163338CVE reference · x_refsource_MISC
- https://owncloud.org/security/advisory/?id=oc-sa-2016-018CVE reference · x_refsource_MISC
- https://github.com/nextcloud/server/commit/68ab8325c799d20c1fb7e98d670785176590e7d0CVE reference · x_refsource_MISC
- https://github.com/owncloud/core/commit/b5a5be24c418033cb2ef965a4f3f06b7b4213845CVE 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.
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.