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Full vulnerability report · 2023
CVE-2023-21707High confidence

Microsoft Exchange Server Remote Code Execution Vulnerability

Microsoft · Microsoft Exchange Server 2013 Cumulative Update 23

8.8HighCVSS 3.1
Recommended action
Within 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
Optional official sources

National CERT insights
?CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

Select the national-authority views to include. The exact source language is shown on each matched advisory. Your choice is remembered on this device and encoded in the shareable URL.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2023-25874

No EUVD known-exploited evidence

Microsoft Exchange Server Remote Code Execution Vulnerability

EUVD state
Present in the current official mapping
Known exploitation
Not present in the current ENISA EUVD known-exploited dataset. This is not proof of no exploitation.
ENISA score
8.8 · CVSS 3.1
Advisory evidence
No linked advisory details stored yet
Recommended actionWithin 7 days

High technical severity; prioritise exposed affected systems while verifying vendor guidance.

Patch available
01

What, why and how

Microsoft Exchange Server Remote Code Execution Vulnerability

What

Microsoft Exchange Server Remote Code Execution Vulnerability

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

What

Microsoft Exchange Server Remote Code Execution Vulnerability

Why

Attacker-influenced serialised data is reconstructed as trusted objects, which can invoke dangerous application behaviour.

How

An attacker operating through a network path may attempt exploitation with low privileges. If successful, the issue may execute code or commands in the affected security context.

02

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
No confirmed evidence

No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
a network path → Deserialization of Untrusted Data → execute code or commands in the affected security context
Attack surface
Network
Privileges required
Low: a basic authenticated account is required
User interaction
None
Attack complexity
Low: no specialised conditions are recorded
Security boundary
Unchanged: impact remains within the vulnerable component's security authority
Weakness
?CWE means Common Weakness Enumeration: a standard category for the underlying weakness.
CWE-502 ↗

CWE-502: Deserialization of Untrusted Data. The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.
NetworkRemote code executionCWE-502
A

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2023-25874Official EUVD mapping

Microsoft Exchange Server Remote Code Execution Vulnerability

Official EUVD record
BSI · German · WID-SEC-W-2023-0368Microsoft Exchange: Mehrere Schwachstellen ermöglichen Codeausführung

Ein entfernter, authentisierter Angreifer kann mehrere Schwachstellen in Microsoft Exchange Server 2013, Microsoft Exchange Server 2016 und Microsoft Exchange Server 2019 ausnutzen, um beliebigen Programmcode auszuführen.

Official advisory
CERT-FR · French · CERTFR-2023-AVI-0133Multiples vulnérabilités dans les produits Microsoft

février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21572 Bulletin de sécurité Microsoft CVE-2023-21573 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21573 Bulletin de sécurité Microsoft CVE-2023-21704 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21704 Bulletin de sécurité Microsoft CVE-2023-21705 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21705 Bulletin de sécurité Microsoft CVE-2023-21706 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21706 Bulletin de sécurité Microsoft CVE-2023-21707 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21707 Bulletin de sécurité Microsoft CVE-2023-21710 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21710 Bulletin de sécurité Microsoft CVE-2023-21713 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21713 Bulletin de sécurité Microsoft CVE-2023-21714 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21714 Bulletin de sécurité Microsoft CVE-2023-21715 du 14 février 2023 https://msrc.microsoft.com/update-guide/vulnerability/CVE-2023-21715 Bulletin de sécurité Micr

Official advisory
03

Patch and workaround

Operational remediation based on structured source evidence.

Status
?Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.
Patch available
Affected
15.00.0 < 15.00.1497.048; 15.01.0 < 15.01.2507.023; 15.02.0 < 15.02.0986.042; 15.02.0 < 15.02.1118.026
Fixed
An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
Action
Review the linked authoritative reference and apply the recorded fixed release appropriate to the affected product branch.
Workaround
No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.
04

Evidence and provenance

Published 14 Feb 2023 · Last source change 19 Aug 2026, 16:26 UTC · CWE-502 · Deserialization of Untrusted Data

CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source
?The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.
FIRST · tracked since 2026-08-14
European sourceENISA EUVD · EUVD-2023-25874
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceOther authority
NVD statusNVD modified after enrichment

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates →
  1. Affected versionsThe structured affected or fixed version information changed.
    Before
    15.01.0 < 15.01.2507.023; 15.02.0 < 15.02.1118.026; 15.02.0 < 15.02.0986.042; 15.00.0 < 15.00.1497.048 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    After
    15.00.0 < 15.00.1497.048; 15.01.0 < 15.01.2507.023; 15.02.0 < 15.02.0986.042; 15.02.0 < 15.02.1118.026 · Fixed: An authoritative update reference is available, but the fixed version is not recorded in the structured CVE fields. Check the linked vendor advisory for the applicable release.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Fixed release or patch reference recorded
ENISA EUVD · EUVD-2023-25874↗CVE authority or vendor reference↗Official CVE record (CNA and ADP data)↗NVD record↗
Technical terms and abbreviations used in this report
CVE
Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS
Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS
Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE
Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA
CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP
Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD
National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT
A computer security incident response team that publishes warnings or coordinates incident response.
PoC
Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF
Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL
Living off the land: abuse of legitimate tools or system functions during an attack.
Free version - for non-commercial use only.CVE-2023-21707 · cve.blacktree.nl