Auth bypass in Microsoft Exchange Server
CVE-2020-0688
A remote code execution vulnerability exists in Microsoft Exchange software when the software fails to properly handle objects in memory, aka 'Microsoft Exchange Memory Corruption Vulnerability'.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.8 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
EPSS exploit prediction
EPSS: 1.000 (100.0th percentile), scored .
Very high probability of exploitation in the next 30 days — among the top 0.1% most-likely-to-be-exploited CVEs. 100th percentile — 100.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
The 30-day trend appears once there are two daily scores.
Affected products
- Microsoft Exchange Server — versions 2010, 2013, 2016
- Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 30 — versions unspecified
- Microsoft Exchange Server 2013 — versions Cumulative Update 23
- Microsoft Exchange Server 2016 Cumulative Update 14 — versions unspecified
- Microsoft Exchange Server 2016 Cumulative Update 15 — versions unspecified
- Microsoft Exchange Server 2019 Cumulative Update 3 — versions unspecified
- Microsoft Exchange Server 2019 Cumulative Update 4 — versions unspecified
Weakness classification (CWE)
CISA KEV (Known Exploited Vulnerabilities)
This CVE is on the CISA KEV catalog, added on . CISA KEV inclusion means CISA has confirmed in-the-wild exploitation; US federal agencies are required to remediate within a published due date.
BOD 22-01 due date: .
Required action: Apply updates per vendor instructions.
Known ransomware campaign use: yes.
Public proof-of-concept exploits
References
- portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2020-0688 (Patch, Vendor Advisory)
- www.zerodayinitiative.com/advisories/ZDI-20-258/ (VDB Entry, Third Party Advisory)
- packetstormsecurity.com/files/156592/Microsoft-Exchange-2019-15.2.221.12-Remote… (Exploit, VDB Entry, Third Party Advisory)
- packetstormsecurity.com/files/156620/Exchange-Control-Panel-Viewstate-Deseriali… (Exploit, VDB Entry, Third Party Advisory)
- 134c704f-9b21-4f2e-91b3-4a467353bcc0 (US Government Resource)
Frequently asked questions
- What is CVE-2020-0688?
- CVE-2020-0688 is a high-severity vulnerability in Microsoft Exchange Server, classified under Improper Authentication. CVSS score: 8.8/10. Published 2020-02-11.
- How severe is CVE-2020-0688?
- High severity. CVSS v3 base score is 8.8 out of 10.
- Is CVE-2020-0688 known to be exploited?
- Yes. CVE-2020-0688 is listed in the CISA Known Exploited Vulnerabilities catalog (added 2021-11-03), indicating it is being actively exploited. 202 public proof-of-concept repositories are indexed.