Security readout for executives and security teams
Plain-English summary
CVE-2023-35311 is a Microsoft Outlook security feature bypass affecting several Office and Microsoft 365 Outlook deployments. It requires user interaction but is listed in CISA KEV, so organizations should treat it as actively exploited and prioritize patch verification on user workstations.
Executive priority
Treat this as a high-priority workstation patching issue because it affects Outlook, requires only user interaction, has high impact scoring, and is in CISA KEV. Focus on rapid update verification rather than waiting for additional exploit details.
Technical view
Microsoft describes this as an Outlook security feature bypass with CVSS 8.8, network attack vector, low complexity, no privileges, and user interaction required. The bundle maps it to CWE-367 and lists Microsoft 365 Apps for Enterprise, Office 2019/LTSC 2021, and Outlook 2013/2016 variants as affected.
Likely exposure
Exposure is most likely on endpoints running affected Microsoft Outlook or Office versions, especially where email is a primary workflow. The provided affected list includes Microsoft 365 Apps for Enterprise, Office 2019, Office LTSC 2021, Outlook 2016, and Outlook 2013/SP1.
Exploitation context
Active exploitation is supported by CISA KEV inclusion. The bundle does not provide exploit mechanics, targeting details, or public proof-of-concept information. The CVSS vector indicates a remote attacker needs the user to interact with malicious content.
Researcher notes
The available sources establish affected Microsoft products, CVSS, CWE-367, vendor advisory presence, and KEV exploitation status. They do not provide safe technical root-cause detail, exploit indicators, or detailed mitigation text beyond Microsoft update guidance.
Mitigation direction
- Apply Microsoft updates referenced in the MSRC advisory for CVE-2023-35311.
- Prioritize endpoints running affected Outlook and Office versions.
- Confirm Microsoft 365 Apps update channels are current.
- Use CISA KEV status to drive remediation urgency.
- Check Microsoft guidance for any environment-specific mitigations.
Validation and detection
- Inventory Outlook and Office versions across managed endpoints.
- Compare installed versions against the affected products in the CVE bundle.
- Verify patch status against the MSRC advisory for CVE-2023-35311.
- Confirm vulnerable builds are no longer present after update rollout.
- Review security monitoring for suspicious Outlook-driven activity.
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-367: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. 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-2023-35311 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
- 8.8 (3.1)
- Known Exploited
- Yes
- Published
Vector: 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
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.
CISA KEV status
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:U/C:H/I:H/A:H/E:F/RL:O/RC:C2.85.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
8.8HighVector: 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
Source materials
- CVE List V5 sourceCVE List V5
- Microsoft Outlook Security Feature Bypass VulnerabilityCVE reference · vendor-advisory
- https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2023-35311CVE reference · government-resource
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.
Time-of-check Time-of-use (TOCTOU) Race Condition
Time-of-check Time-of-use (TOCTOU) Race Condition represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.