cbcvebase.
CVE-2023-35311
published 2023-07-11

CVE-2023-35311: Microsoft Outlook Security Feature Bypass Vulnerability

PriorityP180high7.5CVSS 3.1
AVNACHPRNUIRSUCHIHAH
KEVITW
CISA Known Exploited Vulnerabilitydue 2023-08-01
Exploited in the wild
EPSS
15.52%
96.4th percentile
Microsoft Outlook Security Feature Bypass Vulnerability

Affected

19 ranges
VendorProductVersion rangeFixed in
microsoftmicrosoft_365_apps_for_enterprise>= 16.0.1 < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
microsoftmicrosoft_office_2019>= 19.0.0 < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
microsoftmicrosoft_office_ltsc_2021>= 16.0.1 < https://aka.ms/OfficeSecurityReleaseshttps://aka.ms/OfficeSecurityReleases
microsoftmicrosoft_outlook_2013>= 14.0.0 < 15.0.5571.100015.0.5571.1000
microsoftmicrosoft_outlook_2013_service_pack_1>= 15.0.0.0 < 15.0.5571.100015.0.5571.1000
microsoftmicrosoft_outlook_2016>= 16.0.0.0 < 16.0.5404.100016.0.5404.1000
microsoftoffice
microsoftoffice_long_term_servicing_channel
microsoftoutlook
microsoftoutlook
msrcmicrosoft_365_apps_for_enterprise_for_32-bit_systems
msrcmicrosoft_365_apps_for_enterprise_for_64-bit_systems
msrcmicrosoft_office_2019_for_32-bit_editions
msrcmicrosoft_office_2019_for_64-bit_editions
msrcmicrosoft_office_ltsc_2021_for_32-bit_editions
msrcmicrosoft_office_ltsc_2021_for_64-bit_editions
msrcmicrosoft_outlook_2013
msrcmicrosoft_outlook_2013_rt_service_pack_1
msrcmicrosoft_outlook_2016

Detection & IOCsextracted from sources · hover to see the quote

hash07377209fe68a98e9bca310d9749daa4eb79558e9fc419cf0b02a9e37679038d
hash1a7bb878c826fe0ca9a0677ed072ee9a57a228a09ee02b3c5bd00f54f354930f
hash3a3138c5add59d2172ad33bc6761f2f82ba344f3d03a2269c623f22c1a35df97
hasha61b2eafcf39715031357df6b01e85e0d1ea2e8ee1dfec241b114e18f7a1163f
hashe7cfeb023c3160a7366f209a16a6f6ea5a0bc9a3ddc16c6cba758114dfe6b539
ip74.50.94.156
ip104.234.239.26
ip94.232.40.34
ip66.23.226.102
filenamestart.xml
registryHKLM\SOFTWARE\Policies\Microsoft\Internet Explorer\Main\FeatureControl\FEATURE_BLOCK_CROSS_PROTOCOL_FILE_NAVIGATION
  • Detect child processes spawned by Microsoft Office applications on Windows, which may indicate exploitation of CVE-2023-35311 or related chained vulnerabilities
  • CVE-2023-35311 exploitation requires the victim to click a specially crafted URL in Outlook; the Preview Pane is also an attack vector. Monitor for Outlook opening UNC, SMB, or file:// type URLs as a suspicious indicator
  • The attacker bypasses the Microsoft Outlook Security Notice prompt; alert on Outlook processes that navigate to external URLs without triggering the standard security warning dialog
  • Storm-0978/RomCom is likely to chain CVE-2023-35311 with CVE-2023-32049 (SmartScreen bypass) and CVE-2023-36884 (Office/Windows HTML RCE); correlate detections across these three CVEs for the same host/user
  • ·The four C2 IP addresses (74.50.94.156, 104.234.239.26, 94.232.40.34, 66.23.226.102) and the five SHA-256 hashes are attributed to the broader Storm-0978/RomCom campaign (CVE-2023-36884 chain); they are associated with the campaign context in which CVE-2023-35311 is chained, not exclusively tied to CVE-2023-35311 alone
  • ·After installing the July 2023 Outlook security updates, access to UNC, SMB, and file:// type URLs is restricted to Local, Intranet, or Trusted Sites zones; legitimate internal links may break unless added to the Trusted Site Zone

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
vulncheck8.8HIGH
cisa7.5HIGH
vendor_msrc8.8HIGH
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