Known Exploited Vulnerability
9.8
CRITICAL
CVE-2021-34523
Microsoft Exchange Server Privilege Escalation Vul - [Actively Exploited]
Description

Microsoft Exchange Server Elevation of Privilege Vulnerability

INFO

Published Date :

July 14, 2021, 6:15 p.m.

Last Modified :

Nov. 21, 2024, 6:10 a.m.

Source :

[email protected]

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

3.9
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

Microsoft Exchange Server contains an unspecified vulnerability that allows for privilege escalation.

Required Action :

Apply updates per vendor instructions.

Notes :

https://nvd.nist.gov/vuln/detail/CVE-2021-34523

Public PoC/Exploit Available at Github

CVE-2021-34523 has a 32 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

Affected Products

The following products are affected by CVE-2021-34523 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Microsoft exchange_server
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2021-34523.

URL Resource
http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html Exploit Third Party Advisory VDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 Patch Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-822/ Third Party Advisory VDB Entry
http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html Exploit Third Party Advisory VDB Entry
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 Patch Vendor Advisory
https://www.zerodayinitiative.com/advisories/ZDI-21-822/ Third Party Advisory VDB Entry

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
pwnlog/ALinks

Collection of links for AD purple teamers.

Updated: 4 weeks, 1 day ago
0 stars 0 fork 0 watcher
Born at : Feb. 17, 2024, 2:49 p.m. This repo has been linked 16 different CVEs too.
Profile Photo
nitish778191/fitness_app

None

Updated: 4 months, 3 weeks ago
0 stars 0 fork 0 watcher
Born at : Sept. 4, 2023, 6:14 a.m. This repo has been linked 25 different CVEs too.
Profile Photo
SUPRAAA-1337/CVE-2021-34523

test-yaml

Updated: 9 months ago
2 stars 0 fork 0 watcher
Born at : Sept. 2, 2023, 12:26 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
CVEDB/awesome-cve-repo

None

Shell

Updated: 2 weeks, 3 days ago
3 stars 2 fork 2 watcher
Born at : March 23, 2023, 4:32 a.m. This repo has been linked 267 different CVEs too.
Profile Photo
CVEDB/top

None

Shell

Updated: 2 weeks, 3 days ago
1 stars 0 fork 0 watcher
Born at : March 19, 2023, 1:53 a.m. This repo has been linked 267 different CVEs too.
Profile Photo
laoqin1234/https-github.com-HackingCost-AD_Pentest

None

Updated: 1 year, 8 months ago
1 stars 2 fork 2 watcher
Born at : Nov. 20, 2022, 3:38 a.m. This repo has been linked 18 different CVEs too.
Profile Photo
weeka10/-hktalent-TOP

None

Shell

Updated: 1 year, 9 months ago
2 stars 0 fork 0 watcher
Born at : Nov. 16, 2022, 9:38 a.m. This repo has been linked 256 different CVEs too.
Profile Photo
HackingCost/AD_Pentest

红队|域渗透重要漏洞汇总(持续更新)

Updated: 1 month ago
271 stars 37 fork 37 watcher
Born at : Nov. 15, 2022, 2:23 a.m. This repo has been linked 20 different CVEs too.
Profile Photo
cyberanand1337x/bug-bounty-2022

None

Updated: 1 year, 11 months ago
0 stars 0 fork 0 watcher
Born at : Sept. 30, 2022, 6:29 p.m. This repo has been linked 253 different CVEs too.
Profile Photo
jbmihoub/all-poc

None

Shell

Updated: 4 months, 2 weeks ago
1 stars 2 fork 2 watcher
Born at : Aug. 25, 2022, 12:16 a.m. This repo has been linked 250 different CVEs too.
Profile Photo
Astrogeorgeonethree/Starred2

A curated list of my GitHub Stars

Updated: 6 months ago
1 stars 1 fork 1 watcher
Born at : July 5, 2022, 7:40 p.m. This repo has been linked 32 different CVEs too.
Profile Photo
kh4sh3i/ProxyShell

CVE-2021-34473 Microsoft Exchange Server Remote Code Execution Vulnerability

Python

Updated: 2 months ago
33 stars 6 fork 6 watcher
Born at : June 29, 2022, 12:37 p.m. This repo has been linked 4 different CVEs too.
Profile Photo
merlinepedra/RedTeam_toolkit

None

Dockerfile Python Shell CSS JavaScript HTML

Updated: 2 years, 5 months ago
2 stars 0 fork 0 watcher
Born at : June 26, 2022, 2:40 a.m. This repo has been linked 5 different CVEs too.
Profile Photo
merlinepedra25/RedTeam_toolkit

None

Dockerfile Python Shell CSS JavaScript HTML

Updated: 4 months, 1 week ago
1 stars 0 fork 0 watcher
Born at : June 26, 2022, 2:40 a.m. This repo has been linked 5 different CVEs too.
Profile Photo
kh4sh3i/exchange-penetration-testing

The great Microsoft exchange hack: A penetration tester’s guide (exchange penetration testing)

exchange mail pentest pentest-tool pentesting redteam exchange-server exploit zeroday

Python PowerShell C#

Updated: 2 weeks, 4 days ago
81 stars 22 fork 22 watcher
Born at : June 23, 2022, 11:21 a.m. This repo has been linked 9 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2021-34523 vulnerability anywhere in the article.

  • BleepingComputer
CISA says BianLian ransomware now focuses only on data theft

The BianLian ransomware operation has shifted its tactics, becoming primarily a data theft extortion group, according to an updated advisory from the U.S. Cybersecurity & Infrastructure Security Agenc ... Read more

Published Date: Nov 21, 2024 (1 month ago)
CVE-2022-37969 CVE-2021-34523 CVE-2021-34473 CVE-2021-31207
  • AttackIQ
Response to CISA Advisory (AA24-317A): 2023 Top Routinely Exploited Vulnerabilities

On November 12, 2024, the U.S. Cybersecurity & Infrastructure Security Agency (CISA) released a Cybersecurity Advisory (CSA) providing details on the Common Vulnerabilities and Exposures (CVEs) routin ... Read more

Published Date: Nov 13, 2024 (1 month, 1 week ago)
CVE-2023-4966 CVE-2023-34362 CVE-2023-27350 CVE-2022-47966 CVE-2022-42475 CVE-2022-26134 CVE-2021-4034 CVE-2021-44228 CVE-2021-40539 CVE-2021-34523 ...+4 more CVE
  • The Hacker News
Chinese-Speaking Hacker Group Targets Human Rights Studies in Middle East

Unnamed government entities in the Middle East and Malaysia are the target of a persistent cyber campaign orchestrated by a threat actor known as Tropic Trooper since June 2023. "Sighting this group's ... Read more

Published Date: Sep 05, 2024 (3 months, 2 weeks ago)
CVE-2023-26360 CVE-2021-34523 CVE-2021-34473 CVE-2021-31207
  • Kaspersky
Tropic Trooper spies on government entities in the Middle East

Executive summary Tropic Trooper (also known as KeyBoy and Pirate Panda) is an APT group active since 2011. This group has traditionally targeted sectors such as government, healthcare, transportation ... Read more

Published Date: Sep 05, 2024 (3 months, 2 weeks ago)
CVE-2023-26360 CVE-2021-34523 CVE-2021-34473 CVE-2021-31207
  • Google Cloud
Ransomware Rebounds: Extortion Threat Surges in 2023, Attackers Rely on Publicly Available and Legitimate Tools

Written by: Bavi Sadayappan, Zach Riddle, Jordan Nuce, Joshua Shilko, Jeremy Kennelly A version of this blog post was published to the Mandiant Advantage portal on April 18, 2024. Executive Summary In ... Read more

Published Date: Jun 03, 2024 (6 months, 2 weeks ago)
CVE-2023-22518 CVE-2023-46604 CVE-2023-4966 CVE-2023-40044 CVE-2023-20269 CVE-2023-3519 CVE-2023-3539 CVE-2023-28252 CVE-2023-24880 CVE-2022-47966 ...+11 more CVE

The following table lists the changes that have been made to the CVE-2021-34523 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html
    Added Reference https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523
    Added Reference https://www.zerodayinitiative.com/advisories/ZDI-21-822/
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Modified Analysis by [email protected]

    Feb. 13, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Dec. 28, 2023

    Action Type Old Value New Value
    Changed Description Microsoft Exchange Server Elevation of Privilege Vulnerability This CVE ID is unique from CVE-2021-33768, CVE-2021-34470. Microsoft Exchange Server Elevation of Privilege Vulnerability
    Added CVSS V3.1 Microsoft Corporation AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
  • CWE Remap by [email protected]

    Jul. 12, 2022

    Action Type Old Value New Value
    Changed CWE CWE-269 CWE-287
  • Modified Analysis by [email protected]

    Sep. 21, 2021

    Action Type Old Value New Value
    Changed Reference Type http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html No Types Assigned http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry
  • CVE Modified by [email protected]

    Aug. 20, 2021

    Action Type Old Value New Value
    Added Reference http://packetstormsecurity.com/files/163895/Microsoft-Exchange-ProxyShell-Remote-Code-Execution.html [No Types Assigned]
  • Initial Analysis by [email protected]

    Jul. 22, 2021

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:P/I:P/A:P)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 No Types Assigned https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-34523 Patch, Vendor Advisory
    Changed Reference Type https://www.zerodayinitiative.com/advisories/ZDI-21-822/ No Types Assigned https://www.zerodayinitiative.com/advisories/ZDI-21-822/ Third Party Advisory, VDB Entry
    Added CWE NIST CWE-269
    Added CPE Configuration OR *cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_20:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_9:*:*:*:*:*:*
  • CVE Modified by [email protected]

    Jul. 19, 2021

    Action Type Old Value New Value
    Added Reference https://www.zerodayinitiative.com/advisories/ZDI-21-822/ [No Types Assigned]
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2021-34523 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2021-34523 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

95.88 }} 11.07%

score

0.99606

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability
: