CVE-2021-26855
Microsoft Exchange Server Remote Code Execution Vu - [Actively Exploited]
Description
Microsoft Exchange Server Remote Code Execution Vulnerability
INFO
Published Date :
March 3, 2021, 12:15 a.m.
Last Modified :
Feb. 15, 2024, 8:18 p.m.
Source :
[email protected]
Remotely Exploitable :
Yes !
Impact Score :
5.9
Exploitability Score :
3.9
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.
Microsoft Exchange Server contains an unspecified vulnerability that allows for remote code execution. This vulnerability is part of the ProxyLogon exploit chain.
Apply updates per vendor instructions.
Reference CISA's ED 21-02 (https://www.cisa.gov/emergency-directive-21-02) for further guidance and requirements.
Public PoC/Exploit Available at Github
CVE-2021-26855 has a 142 public PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
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-2021-26855.
| URL | Resource |
|---|---|
| http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html | Exploit Third Party Advisory VDB Entry |
| http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html | Exploit Third Party Advisory VDB Entry |
| http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html | Exploit Third Party Advisory VDB Entry |
| http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html | Exploit Third Party Advisory VDB Entry |
| https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855 | Patch Vendor Advisory |
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).
None
Python
None
None
Microsoft Exchange/Outlook Offline Address Book (.oab files) decoder
address address-book addressbook csv-export excel-export exchange json-export library microsoft oab offline offline-tool outlook servier table-export tool utility utility-library hubtools security
Makefile Python
None
Go Smarty CSS JavaScript HTML
Lista de Shodan Dorks y herramientas para su uso
Python
None
Go
All CVE - PoC in GitHub
poc proofofconcept tester allcve cvegithub cvenew cvepoc cveupdate
None
Cybersecurity-Handbooks
attack-defense cybersec cybersecurity cybersecurity-education cybersecurity-tools cybersecurity-training reconnaissance cloud cryptography forensics osint password reverse-engineering wireless wireless-security
Collection of links for AD purple teamers.
渗透测试有关的POC、EXP、脚本、提权、小工具等---About penetration-testing python-script poc getshell csrf xss cms php-getshell domainmod-xss csrf-webshell cobub-razor cve rce sql sql-poc poc-exp bypass oa-getshell cve-cms
Assembly Python Shell PHP C++ C Go Ruby HTML Java
An in-depth explanation of how I would conduct a risk assessment from the perspective of a Cyber security analyst.
Clone from gist
Moriarty is designed to enumerate missing KBs, detect various vulnerabilities, and suggest potential exploits for Privilege Escalation in Windows environments.
C#
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2021-26855 vulnerability anywhere in the article.
-
Cybersecurity News
Researcher Identifies ToddyCat-Inspired APT Attack Leveraging ICMP Backdoor and Microsoft Exchange Flaws
Image: KasperskyCybersecurity researchers at Kaspersky’s Global Emergency Response Team (GERT) have uncovered a sophisticated attack involving an ICMP backdoor, bearing striking similarities to the ta ... Read more
-
Kaspersky
A deep dive into the most interesting incident response cases of last year
In 2023, Kaspersky’s Global Emergency Response Team (GERT) participated in services around the world that allowed our experts to gain insight into various threats and techniques used by APT groups, co ... Read more
The following table lists the changes that have been made to the
CVE-2021-26855 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 [email protected]
May. 14, 2024
Action Type Old Value New Value -
Modified Analysis by [email protected]
Feb. 15, 2024
Action Type Old Value New Value -
CVE Modified by [email protected]
Dec. 29, 2023
Action Type Old Value New Value Changed Description Microsoft Exchange Server Remote Code Execution Vulnerability This CVE ID is unique from CVE-2021-26412, CVE-2021-26854, CVE-2021-26857, CVE-2021-26858, CVE-2021-27065, CVE-2021-27078. Microsoft Exchange Server Remote Code Execution Vulnerability Added CVSS V3.1 Microsoft Corporation AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N -
CWE Remap by [email protected]
Jul. 12, 2022
Action Type Old Value New Value Changed CWE NVD-CWE-noinfo CWE-918 -
Modified Analysis by [email protected]
May. 06, 2022
Action Type Old Value New Value Changed Reference Type http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html No Types Assigned http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html Exploit, Third Party Advisory, VDB Entry -
CVE Modified by [email protected]
May. 21, 2021
Action Type Old Value New Value Added Reference http://packetstormsecurity.com/files/162736/Microsoft-Exchange-ProxyLogon-Collector.html [No Types Assigned] -
Modified Analysis by [email protected]
May. 21, 2021
Action Type Old Value New Value Changed Reference Type http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html Exploit, Third Party Advisory http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry Changed Reference Type http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html No Types Assigned http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html Exploit, Third Party Advisory, VDB Entry -
CVE Modified by [email protected]
May. 18, 2021
Action Type Old Value New Value Added Reference http://packetstormsecurity.com/files/162610/Microsoft-Exchange-2019-Unauthenticated-Email-Download.html [No Types Assigned] -
Modified Analysis by [email protected]
Mar. 26, 2021
Action Type Old Value New Value Changed Reference Type http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html No Types Assigned http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html Exploit, Third Party Advisory, VDB Entry Changed Reference Type http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html No Types Assigned http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html Exploit, Third Party Advisory Changed CPE Configuration OR *cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:* OR *cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_21:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_22:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2013:cumulative_update_23:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_10:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_11:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_12:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_13:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_14:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_15:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_16:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_17:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_18:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_8:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_9:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:-:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_1:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_2:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_3:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_4:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_5:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_6:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:* -
CVE Modified by [email protected]
Mar. 23, 2021
Action Type Old Value New Value Added Reference http://packetstormsecurity.com/files/161938/Microsoft-Exchange-ProxyLogon-Remote-Code-Execution.html [No Types Assigned] -
CVE Modified by [email protected]
Mar. 18, 2021
Action Type Old Value New Value Added Reference http://packetstormsecurity.com/files/161846/Microsoft-Exchange-2019-SSRF-Arbitrary-File-Write.html [No Types Assigned] -
Initial Analysis by [email protected]
Mar. 09, 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-2021-26855 No Types Assigned https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2021-26855 Patch, Vendor Advisory Added CWE NIST NVD-CWE-noinfo 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_18:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2016:cumulative_update_19:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_7:*:*:*:*:*:* *cpe:2.3:a:microsoft:exchange_server:2019:cumulative_update_8:*:*:*:*:*:*
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2021-26855 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-2021-26855
weaknesses.
Exploit Prediction
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.
97.46 }} 0.02%
score
0.99967
percentile