Security readout for executives and security teams
Plain-English summary
Collabora Online versions before 6.4.9-5 had a reflected cross-site scripting flaw in iframe creation. A maliciously crafted iframe value could run script in the Collabora Online iframe context and expose limited browser-stored settings plus the session authentication token passed during iframe creation.
Executive priority
Prioritize remediation for internet-facing Collabora Online systems. The flaw is patched and affects session token confidentiality, so delaying upgrade leaves avoidable account and document-access risk even without confirmed exploitation evidence.
Technical view
The issue is CWE-79 reflected XSS in Collabora Online before 6.4.9-5. Unescaped HTML in an iframe creation variable could execute script inside the Collabora Online iframe context. CVSS 3.1 is 7.3 high with network access, low complexity, no privileges, and no user interaction reported.
Likely exposure
Exposure is limited to organizations running Collabora Online versions earlier than 6.4.9-5. The source states Collabora Online 4.2 is not affected. Public-facing or partner-accessible Collabora Online deployments should be prioritized because the weakness is network-reachable according to the CVSS vector.
Exploitation context
The provided sources do not state active exploitation, and the CVE is not marked as KEV. The security impact is still meaningful because successful exploitation could expose a session authentication token and limited user settings within the browser context.
Researcher notes
Analysis is based on the CVE record and GitHub advisory only. The bundle names the patch version and affected range, but does not provide detailed exploit prerequisites, proof of active abuse, or alternate vendor mitigations beyond upgrading.
Mitigation direction
- Upgrade affected Collabora Online deployments to version 6.4.9-5 or later.
- Inventory Collabora Online instances and flag versions earlier than 6.4.9-5.
- Treat Collabora Online 4.2 as unaffected only after confirming the deployed version.
- Review the vendor advisory for deployment-specific guidance and follow-up updates.
- Consider restricting access to affected deployments until the upgrade is complete.
Validation and detection
- Confirm each Collabora Online deployment reports version 6.4.9-5 or later.
- Document any Collabora Online 4.2 deployments separately as not affected per the source.
- Run safe regression testing to confirm iframe inputs are escaped after upgrade.
- Review access logs for unusual iframe creation activity around the disclosure window.
- Verify session token handling assumptions with application owners after remediation.
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 lookupCredential and access behavior lookup
The CVE wording references authentication or credential exposure, so valid-account and credential-access review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2021-32745 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
- 7.3 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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:N/S:U/C:L/I:L/A:L3.93.4Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
7.3HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
Source materials
- CVE List V5 sourceCVE List V5
- https://github.com/CollaboraOnline/online/security/advisories/GHSA-w536-654v-cjj9CVE reference · x_refsource_CONFIRM
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.