MEDIUM
CVE-2020-8633
CWE-281Published: February 18, 2020· Updated: Jun 17, 2026
5.3
CVSS v3.1
Official Description
An issue was discovered in Zimbra Collaboration Suite (ZCS) before 8.8.15 Patch 7. When grantors revoked a shared calendar in Outlook, the calendar stayed mounted and accessible.
Technical Analysis
CVE-2020-8633 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
CVSS v3.1 Vector Breakdown
Exploitability
Attack VectorNetwork
Attack ComplexityLow
Privileges Req.None
User InteractionNone
ScopeUnchanged
Impact
ConfidentialityLow
IntegrityNone
AvailabilityNone
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Affected Vendors & Products
synacor1 product(s)
zimbra collaboration suite
Source: NVD CPE · 2 total CPE entries
Exploit & PoC Resources
NO KNOWN EXPLOITNo public exploit confirmed at this time
Exploit-DB
Offensive Security exploit database
GitHub PoC Search
Community PoC repositories
Rapid7 / Metasploit
Metasploit module search
PacketStorm
Security advisories & exploits
NVD Detail
Official NIST entry
MITRE CVE
CVE Program entry
External links open in a new tab. Always verify in a controlled environment before use.
Official Patches & Advisories
All References (2)
→
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P7Vendor Advisory
→
https://wiki.zimbra.com/wiki/Zimbra_Releases/8.8.15/P7Vendor Advisory
Quick Facts
CVE IDCVE-2020-8633
CVSS Score5.3 / 10
SeverityMEDIUM
WeaknessCWE-281
CISA KEVNo
Affected1 vendor(s)
PublishedFeb 18, 2020
Related CVEs (CWE-281)
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2020-8633 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
Data sourced from NVD (NIST), CISA KEV, and EPSS (FIRST). Analysis generated by CTIWATCH.COM. CVE data is provided under the NVD usage policy.