CVE-2023-35311
Confirmed PUBLISHEDMicrosoft Outlook Security Feature Bypass Vulnerability
Recommended Action
Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
At a Glance
Microsoft Outlook Security Feature Bypass Vulnerability
- CVE Published
- Jul 11, 2023
- Exploitation Reported
- Jul 11, 2023
- CVSS
- 8.8 High
- EPSS
- —
Affected Versions
| Vendor | Product | Version | Status |
|---|---|---|---|
| Microsoft |
Microsoft 365 Apps for Enterprise
|
16.0.1 to < https://aka.ms/OfficeSecurityReleases |
Affected |
| Microsoft |
Microsoft Office LTSC 2021
|
16.0.1 to < https://aka.ms/OfficeSecurityReleases |
Affected |
| Microsoft |
Microsoft Office 2019
|
19.0.0 to < https://aka.ms/OfficeSecurityReleases |
Affected |
| Microsoft |
Microsoft Outlook 2016
|
16.0.0.0 to < 16.0.5404.1000 |
Affected |
| Microsoft |
Microsoft Outlook 2013
|
14.0.0 to < 15.0.5571.1000 |
Affected |
| Microsoft |
Microsoft Outlook 2013 Service Pack 1
|
15.0.0.0 to < 15.0.5571.1000 |
Affected |
CVE References
- Microsoft Outlook Security Feature Bypass Vulnerability msrc.microsoft.com · Vendor Advisory https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-35311
Recommended Actions
- Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.
- Check enrichment artifacts for scanner coverage and available PoCs before rolling remediation validation.
- Use the Pro API to automate enrichment, telemetry, and workflow delivery for VM, SOC, and CTI pipelines.
Known Exploited Vulnerability Sources
Catalogues that list this CVE as a known exploited vulnerability.
Per-source evidence links for KEV attestations are available through the KEVIntel Pro API.
Learn about Pro API access| Source | Added |
|---|---|
| CISA First | 2023-07-11 00:00 UTC |
No detection artifacts or sensor request patterns are available for this CVE yet.
Check back as sensor telemetry and scanner integrations are updated.
Virtual Patch
Compensating WAF rules to help reduce exposure to this CVE. Rule content and deployable vendor exports are available with KEVIntel Enterprise.
KEVIntel does not currently have a virtual patch for this CVE. When available, KEVIntel virtual patches ship as deployable ModSecurity, Cloudflare, and AWS WAF rules.
Enterprise feature. Virtual patch rule content and deployable vendor exports (ModSecurity, Cloudflare, AWS WAF) are available to KEVIntel Enterprise users.
CVSS Scores
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H/E:F/RL:O/RC:C
Exploitation Status
Exploited in the wild
Recorded 2023-07-11 00:00:00 UTC · CISA
Weaknesses (CWE)
-
Time-of-check Time-of-use (TOCTOU) Race Condition
Scanner Integrations
| Scanner | Reference | Detected |
|---|---|---|
| Nessus | https://www.tenable.com/plugins/nessus/178203 | Jun 02, 2025 |
Timeline
Key exploitation, disclosure, scanner coverage, and KEV attestation events for this CVE.
-
09:26 UTC about 1 year ago09:26 UTC · about 1 year ago
Nessus plugin available
Scanner coverage available
-
17:03 UTC about 3 years ago17:03 UTC · about 3 years ago
CVE published
Vulnerability disclosed publicly
-
00:00 UTC about 3 years ago00:00 UTC · about 3 years ago
Added to CISA KEV
Listed in the CISA Known Exploited Vulnerabilities catalog
-
23:09 UTC about 3 years ago23:09 UTC · about 3 years ago
CVE ID reserved
Identifier reserved by the CNA
Automate This Intelligence with the Pro API
Confidence scoring, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.
Pro API Example
GET /api/v2/pro/kevs/CVE-2023-35311
{
"cve_id": "CVE-2023-35311",
"title": "Microsoft Outlook Security Feature Bypass Vulnerability",
"affected_vendor": "Microsoft",
"affected_product": "Microsoft 365 Apps for Enterprise, Microsoft Office LTSC 2021, Microsoft Office 2019, Microsoft Outlook 2016, Microsoft Outlook 2013, Microsoft Outlook 2013 Service Pack 1",
"affected_versions": [
{ "vendor": "...", "product": "...", "status": "affected", "display_label": "..." }
],
"confidence": "Confirmed",
"cvss_score": 8.8,
"epss_score": null,
"exploit_status": {
"exploited_in_the_wild": true,
"active_exploitation_observed": false
},
"sensor_telemetry": { "...": "Pro API fields" },
"proof_of_concepts": [ "..." ],
"scanner_integrations": [ "..." ]
}