Vulnerability report

Trusted Third Party Report Confirmed Confidence In CISA KEV

CVE-2020-0688

Microsoft Exchange Server 2013 Remote Code Execution

Microsoft Exchange Server 2013 · Cumulative Update 23

Watch CVE-2020-0688 Browse KEV feed
Severity
CVSS 8.8 · High
Confidence
Confirmed
Exploit status
Trusted Third Party Report
EPSS
100.0%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2020-0688 is a vulnerability affecting Microsoft Exchange Server 2013 and 5 other products.

Have exploitation attempts been observed?

Yes. Exploitation attempts have been reported for this vulnerability. Previdian lists it as a known exploited vulnerability. Listed in CISA KEV. Confidence is confirmed.

Who is affected?

Affected products include Microsoft Exchange Server 2013 and 5 other products, including Cumulative Update 23 and unspecified.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Microsoft Exchange Server 2013 Remote Code Execution

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'.

Microsoft Affected
Microsoft Exchange Server 2013
Cumulative Update 23
Microsoft Affected
Microsoft Exchange Server 2019 Cumulative Update 3
unspecified
Microsoft Affected
Microsoft Exchange Server 2016 Cumulative Update 14
unspecified
Microsoft Affected
Microsoft Exchange Server 2016 Cumulative Update 15
unspecified
Microsoft Affected
Microsoft Exchange Server 2019 Cumulative Update 4
unspecified
Microsoft Affected
Microsoft Exchange Server 2010 Service Pack 3 Update Rollup 30
unspecified
Published
11 Feb 2020
Exploitation Attempts Reported
03 Nov 2021
Attack vector
Remote
Complexity
Low
Privileges
Low
User interaction
None

Tags

malware cisa metasploit microsoft ransomware metasploit_scanner

CVE References

Exploitation evidence

Evidence of exploitation attempts

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploitation Attempts Observed in the Wild

CISA

Recorded 03 Nov 2021

A trusted third party reported exploitation attempts.

Targeted by Malware-Related Exploitation Attempts

CISA

Recorded 03 Nov 2021

Exploitation attempts against this vulnerability are associated with malware-related payloads.

Proof of concept available

Recorded 28 Apr 2025

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2021-11-03 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Metasploit https://github.com/rapid7/metasploit-framework/blob/master/modules/exploits/windows/http/exchange_ecp_viewstate.rb 28 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

8.8 High

Potential damage if exploited. Separate from whether attackers are using it.

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS

100.0%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Authentication CWE-287

Recent mention · The Hacker News

Three Threat Groups Target Russian Enterprises With Backdoors, Ransomware, and Wipers

Enterprises in Russia have emerged as the target of three threat activity clusters tracked as NightEagle, Hacking Cat, and Toy Ghouls, according to multiple reports from Kaspersky. The cybersecurity vendor said it has identified attacks mounted by NightEagle (aka APT-Q-95), a...

Read full advisory

All CVSS Scores

CVSS v3.1 8.8 High

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

CVSS v2.0 9.0 High

AV:N/AC:L/Au:S/C:C/I:C/A:C

All Mentions

Recent mention · The Hacker News

Three Threat Groups Target Russian Enterprises With Backdoors, Ransomware, and Wipers

The Hacker News · 16 Sep 2026

Enterprises in Russia have emerged as the target of three threat activity clusters tracked as NightEagle, Hacking Cat, and Toy Ghouls, according to multiple reports from Kaspersky. The cybersecurity vendor said it has identified attacks mounted by NightEagle (aka APT-Q-95), a threat actor known to be active since at least 2023, that involve new techniques for persistence and lateral movement.

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

exchange_ecp_viewstate

metasploit · Created Unknown

Metasploit module for CVE-2020-0688

Timeline

From disclosure to observed exploitation attempts

  1. 15:02 UTC

    Metasploit module available

    Exploit module available

  2. 15:02 UTC

    Public PoC available

    Public proof-of-concept code published

  3. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 00:00 UTC

    Targeted by malware-related exploitation attempts

    Malware-related exploitation attempts or payloads reported

  5. 21:22 UTC

    CVE published

    Vulnerability disclosed publicly

  6. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

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  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2020-0688

Sample API response 
{
  "cve_id": "CVE-2020-0688",
  "confidence": "Confirmed",
  "cvss_score": 8.8,
  "cvss_estimated": false,
  "epss_score": 0.99955,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}