CVE-2024-21413

Published Feb 13, 2024

Last updated 3 months ago

Overview

AI description

Automated description summarized from trusted sources.

CVE-2024-21413 is a remote code execution (RCE) vulnerability affecting Microsoft Outlook. It stems from improper input validation when Outlook processes URLs, particularly those using the `file://` protocol and crafted URL structures. This vulnerability, also known as the "MonikerLink" bug, allows attackers to bypass security protections, such as the Office Protected View, and execute arbitrary code on a victim's machine by sending a malicious email. The vulnerability can be triggered even when previewing a maliciously crafted email. Successful exploitation could lead to remote code execution, theft of NTLM credentials, data exfiltration, data encryption, installation of malware, and potential full system compromise. It affects various versions of Microsoft Outlook, including Microsoft Office 2016, 2019, 2021, and Microsoft 365 Apps.

Description
Microsoft Outlook Remote Code Execution Vulnerability
Source
secure@microsoft.com
NVD status
Analyzed
Products
365_apps, office_2016, office_2019, office_long_term_servicing_channel

Risk scores

CVSS 3.1

Type
Secondary
Base score
9.8
Impact score
5.9
Exploitability score
3.9
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity
CRITICAL

Known exploits

Data from CISA

Vulnerability name
Microsoft Outlook Improper Input Validation Vulnerability
Exploit added on
Feb 6, 2025
Exploit action due
Feb 27, 2025
Required action
Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.

Weaknesses

secure@microsoft.com
CWE-20
nvd@nist.gov
NVD-CWE-noinfo

Social media

Hype score
Not currently trending
  1. 1️⃣ One character bypasses Microsoft security CVE-2024-21413: Add ! to a file:// link in Outlook. User clicks. Windows automatically leaks NTLM credentials. No download. No warning. CVSS 9.8 = critical. One character = Entire network compromised. https://t.co/p3ljypv97E

    @SALIMASSILI2006

    3 Feb 2026

    57 Impressions

    0 Retweets

    0 Likes

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    0 Replies

    0 Quotes

  2. One character can steal your password. Just ! in a file:// link = Windows leaks NTLM credentials. CVE-2024-21413 | CVSS 9.8 Small detail = Massive impact. This is why SOC analysts obsess over "minor" things. #CyberSecurity #SOCAnalyst #ThreatIntel https://t.co/YI8IKuDhuR

    @SALIMASSILI2006

    3 Feb 2026

    66 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  3. Happy new month 🎉 February is here and the grind continues. Wrapped up the Moniker Link module (CVE-2024-21413). Learned how Outlook can leak NTLM hashes via Moniker Links and how to defend against it. #Cybersecurity #LearningInPublic #TechJourney https://t.co/aYMQMi4qlx

    @jeo_crypts

    2 Feb 2026

    55 Impressions

    1 Retweet

    2 Likes

    0 Bookmarks

    1 Reply

    0 Quotes

  4. 📢 𝐇𝐨𝐭 𝐨𝐟𝐟 𝐭𝐡𝐞 𝐩𝐫𝐞𝐬𝐬: 𝐂𝐕𝐄 𝐢𝐧𝐬𝐢𝐠𝐡𝐭𝐬! Discover how UAC-0028 exploits CVE-2024-21413 in Outlook to steal credentials and bypass defenses, with CERT-UA insights and actionable mitigations. 🌐 Explore the

    @PurpleOps_io

    2 Feb 2026

    41 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  5. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/xXyriTmL53 #tryhackme via @tryhackme

    @SultryIce

    31 Jan 2026

    71 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  6. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/yHnA3kLK5h #tryhackme via @tryhackme

    @pooping4poops

    30 Jan 2026

    50 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  7. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/0P3MEzDC6V #tryhackme via @tryhackme

    @J3CHxP

    27 Jan 2026

    43 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  8. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/h0icCCtgXX #tryhackme via @tryhackme

    @mallox_318

    25 Jan 2026

    0 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  9. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/l5wmJlWHhw #tryhackme via @tryhackme

    @MrKiyan404

    22 Jan 2026

    104 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  10. Day 16: my journey on @tryhackme alongside @d4rk_intel > Moniker link Deep dive into CVE-2024-21413, Explored how crafted Outlook links bypass Protected View, enabling credential leaks and potential RCE, alongside detection and mitigation in a lab environment. #cybersecurit

    @Azutech_

    22 Jan 2026

    349 Impressions

    0 Retweets

    7 Likes

    0 Bookmarks

    1 Reply

    0 Quotes

  11. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/40iFhXR2Lq #tryhackme via @tryhackme

    @RedionMeta

    20 Jan 2026

    40 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  12. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/n70Qrl6uev #tryhackme via @tryhackme

    @JayeshV88153533

    19 Jan 2026

    58 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  13. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/9dCBQQsCyk #tryhackme via @tryhackme

    @genius_157

    19 Jan 2026

    53 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  14. Day 14: Moniker Link (CVE-2024-21413) > @tryhackme Today, I took out time to learn about the Moniker Link vulnerability > explored how it's exploited, detected, and fixed. Great to be back in the groove! #OSINT #Cybersecurity https://t.co/LIJx09QEhU

    @d4rk_intel

    17 Jan 2026

    738 Impressions

    1 Retweet

    13 Likes

    3 Bookmarks

    0 Replies

    0 Quotes

  15. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/US7q3Y4PPk #tryhackme via @tryhackme

    @L30_N30_THM

    17 Jan 2026

    50 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  16. MONIKER LINK _CVE-2024-21413(DEMO) CAPTURING NTLM HASH VIA HYPERLINK INJECTION TOOL:RESPONDER https://t.co/v1I1mtoLPK

    @h4ruk7

    14 Jan 2026

    638 Impressions

    0 Retweets

    10 Likes

    5 Bookmarks

    0 Replies

    0 Quotes

  17. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/kdGmfz1cBy #tryhackme via @tryhackme

    @thisguycanhack

    11 Jan 2026

    1 Impression

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  18. Day 10: Completed Moniker Link (CVE-2024-21413) on TryHackMe. Explored how this Windows shortcut vulnerability can be abused to bypass security protections and enable malicious code execution. @purpullgirl #TryHackMe #HandsOn #CyberSecurity https://t.co/3Qvqe04rSd

    @Aboda_lateria

    11 Jan 2026

    130 Impressions

    1 Retweet

    7 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  19. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/6OoOdgvUKm #tryhackme via @tryhackme

    @fwdFLASH

    11 Jan 2026

    48 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  20. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/LFKT7KHxDz #tryhackme via @tryhackme #tryhackme #CVE #leakcredentials #learning

    @LittleSun4lower

    10 Jan 2026

    69 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  21. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe! Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/QY0l0OLzhN #tryhackme via @tryhackme

    @CyberKoroc

    10 Jan 2026

    75 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  22. #Day 2 of my #ZeroToProHacker journey.​ Today I learned what Moniker Link (CVE-2024-21413) is and how it can be used to capture NetNTLMv2 hashes by sending a crafted link that forces the victim to authenticate to an attacker-controlled SMB share https://t.co/l2ppfCJb9b

    @JaatYogesh57183

    5 Jan 2026

    13 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  23. CVE-2024-21413 breakdown: Outlook + file:// link + ! character = NTLM credential leak. No download. No malware. Just one click. Windows automatically tries to authenticate to the attacker's server. Credentials sent. This is why security isn't about "big vulnerabilities." https://

    @SALIMASSILI2006

    4 Jan 2026

    85 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  24. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. https://t.co/eBUehYQIq0 #tryhackme via @tryhackme

    @AhmedZerocool

    2 Jan 2026

    34 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  25. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/BanSFr7u6X #tryhackme via @tryhackme

    @CHIKA_DIBIA24

    27 Dec 2025

    43 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  26. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/OTwhrggLxr #tryhackme via @tryhackme

    @gpmohanraj_2003

    22 Dec 2025

    64 Impressions

    0 Retweets

    0 Likes

    1 Bookmark

    0 Replies

    0 Quotes

  27. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/lwvEaiiCj1 #tryhackme via @tryhackme

    @VoiceJustdoit

    15 Dec 2025

    33 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  28. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/ua61gJ8gHv #tryhackme via @tryhackme

    @BroodaShah

    12 Dec 2025

    36 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  29. #RaiseTech #tryhackme 🌟2025.12.06(夜) 《THM》DAY12:Moniker Link (CVE-2024-21413):1時間 ✍感想 ・Outlookで、リンクをクリックしての脆弱性(PoC)について学びました。 ・定期的にアップデートを心掛ける。 ・Pythonは

    @akky743793

    6 Dec 2025

    89 Impressions

    0 Retweets

    2 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  30. #100DaysOfCybersecurity Day 4/100: My Security + exam is next Monday! - Did 25 questions for my upcoming Security + exam from Dark Bird Tech Channel on Youtube - TryHackMe: Finished Moniker Link (CVE-2024-21413) room from CyberSecurity 101 path and AI in Security - old

    @thecybernovice

    4 Dec 2025

    8 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    1 Reply

    0 Quotes

  31. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/jxI0rtja03 #tryhackme via @tryhackme #CyberSecurity #tryhackme

    @SALIMASSILI2006

    3 Dec 2025

    53 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  32. برای outlook آسیب پذیری با کد شناسایی CVE-2024-21413 از نوع RCE منتشر شده است که به هکرها امکان اجرای کد روی سیستم آسیب پذیر از طریق دستکاری ایمیل را می دهد. این آسیب پذ

    @AmirHossein_sec

    2 Dec 2025

    67 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  33. 🚨 Confirmado: PoC liberado + explotación activa del RCE en Outlook (CVE-2024-21413). Riesgo máximo: robo de NTLM y control total del sistema. Parchear es urgente. En LUER te ayudamos. #Ciberseguridad #Outlook #RCE https://t.co/qmsokZd4iQ

    @Luer_CS

    2 Dec 2025

    81 Impressions

    2 Retweets

    2 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  34. 🛡️ Ya existe un exploit público para un fallo crítico de Outlook Microsoft corrigió hace meses una vulnerabilidad muy grave en Outlook (CVE-2024-21413, severidad 9.8). Ahora apareció un PoC público: código que demuestra cómo explotarla. Cuando eso pasa otros actore

    @CycuraMX

    1 Dec 2025

    8116 Impressions

    39 Retweets

    128 Likes

    58 Bookmarks

    2 Replies

    0 Quotes

  35. Outlookの遠隔コード実行脆弱性MonikerLink (CVE-2024-21413)に対応するPoC(攻撃の概念実証コード)が公表された。OulookのプレビューペインからゼロクリックでNTLMハッシュを抜ける。 https://t.co/gORtmBe6Bt

    @__kokumoto

    1 Dec 2025

    1076 Impressions

    2 Retweets

    3 Likes

    5 Bookmarks

    0 Replies

    0 Quotes

  36. A Proof-of-Concept (PoC) exploit code has been released for a critical remote code execution (RCE) vulnerability in Microsoft Outlook, identified as CVE-2024-21413. #cybersecurity https://t.co/yvuT426D1S

    @dan_covic

    1 Dec 2025

    11 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  37. 🚨 PoC Exploit Released For Outlook 0-Click Remote Code Execution Vulnerability Source: https://t.co/zpeuGMQuHa A Proof-of-Concept (PoC) exploit code has been released for a critical remote code execution (RCE) vulnerability in Microsoft Outlook, identified as CVE-2024-21413

    @The_Cyber_News

    1 Dec 2025

    30338 Impressions

    129 Retweets

    363 Likes

    192 Bookmarks

    6 Replies

    0 Quotes

  38. Outlookの深刻なRCE脆弱性を悪用するPoCが公開され、保護ビューをすり抜けてコード実行や認証情報漏えいを招く攻撃手法が明らかになった。クリックだけで被害に至る可能性があるため警戒が必要だ。 問題のC

    @yousukezan

    1 Dec 2025

    10125 Impressions

    29 Retweets

    90 Likes

    57 Bookmarks

    0 Replies

    5 Quotes

  39. GitHub - mmathivanan17/CVE-2024-21413: Outlook exploitation https://t.co/rm5h2PquJ7

    @akaclandestine

    30 Nov 2025

    1910 Impressions

    8 Retweets

    22 Likes

    9 Bookmarks

    0 Replies

    0 Quotes

  40. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/IBtyxaJ3ev #tryhackme via @tryhackme @ireteeh

    @bajboybountyII

    27 Nov 2025

    84 Impressions

    0 Retweets

    2 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  41. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/buqo7zYsOU #tryhackme via @tryhackme

    @AdamNugent28159

    26 Nov 2025

    1 Impression

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  42. I completed the Moniker Link (CVE-2024-21413) room on TryHackMe, where I learned how the vulnerability works, how it bypasses Outlook’s Protected View, and how it can be used to leak user credentials https://t.co/MY5MhXOGJt #tryhackme via @tryhackme

    @omo_aremu_

    26 Nov 2025

    40 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  43. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/jF4kHDHiVW #tryhackme via @tryhackme

    @Ezekieluche_

    25 Nov 2025

    50 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  44. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/hqqd207JHR #tryhackme via @tryhackme

    @Martinko228O

    25 Nov 2025

    0 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  45. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/MKME4nuYNW #tryhackme @tryhackmeより

    @GrapheneHackSec

    25 Nov 2025

    0 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  46. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/QVMfDrtaeH #tryhackme via @tryhackme

    @0xTreasureSec

    23 Nov 2025

    40 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  47. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/1K9slMn9qQ #tryhackme via @tryhackme

    @terrorCHrist

    23 Nov 2025

    62 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  48. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. Leak user's credentials using CVE-2024-21413 to bypass Outlook's Protected View. https://t.co/NH4KSXymnD #tryhackme via @tryhackme

    @0xiv4n

    16 Nov 2025

    64 Impressions

    0 Retweets

    1 Like

    0 Bookmarks

    0 Replies

    0 Quotes

  49. #tryhackme「Moniker Link (CVE-2024-21413)」ルームをクリアしました! 簡単なHTMLリンクがどのようにしてOutlookの保護ビューを回避し、SMB経由でNTLMv2ハッシュを漏洩するのかを知ることができました。 https://t.co/bP0NO1YeMH

    @vivi_cyber

    16 Nov 2025

    3 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

  50. I just completed Moniker Link (CVE-2024-21413) room on TryHackMe. It was really interesting to learn how a simple HTML hyperlink could bypass Outlook’s Protected View and leak NTLMv2 hashes through SMB. https://t.co/bP0NO1YeMH #tryhackme via @tryhackme #CybersecurityTraining

    @vivi_cyber

    16 Nov 2025

    3 Impressions

    0 Retweets

    0 Likes

    0 Bookmarks

    0 Replies

    0 Quotes

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