ONSEC Cyber Daily - July 21, 2025 Welcome to today's edition of ONSEC Cyber Daily, where we unravel the latest in the world of cybersecurity. Today, we delve into a gripping narrative of digital warfare, as Microsoft finds itself at the epicenter of a relentless cyber onslaught. A series of critical vulnerabilities have been unearthed, with SharePoint servers bearing the brunt of zero-day exploits, leaving global organizations scrambling for security patches. As Chinese hackers target remote management tools, and malicious RAR5 files crash systems via a new 7-Zip vulnerability, the urgency for robust cybersecurity measures has never been more pressing. Join us as we explore the unfolding saga of Microsoft's battle against unseen adversaries, and the race to fortify digital defenses in an increasingly perilous cyber landscape. Stay informed, stay secure.

Exploits Alert

1. Microsoft Server Software Comes Under Widespread Cyberattack. Microsoft has been grappling with a series of cyberattacks, with recent warnings highlighting that Chinese hackers are targeting remote management tools and cloud services. This has raised significant concerns about the security of Microsoft's server software, as these attacks could potentially compromise sensitive data and disrupt operations. The situation underscores the need for robust cybersecurity measures to protect against such sophisticated threats. Source
2. New 7-Zip Vulnerability Enables Malicious RAR5 File to Crash Your System. A new vulnerability in 7-Zip has been discovered, allowing malicious RAR5 files to crash systems. This is particularly alarming as archive files are increasingly used in cyberattacks, making up 39% of all malware. Users are urged to update their software and exercise caution when handling archive files to mitigate potential risks. Source
3. Microsoft Warns Of Major SharePoint Zero‑Day Attack Targeting Government & Enterprise Servers. Microsoft has issued a warning about a zero-day vulnerability in SharePoint server software, which is being actively exploited in cyberattacks targeting government and enterprise servers. This vulnerability poses a significant threat, potentially allowing attackers to gain unauthorized access to sensitive information. Organizations are advised to apply security patches promptly to protect their systems. Source
4. Microsoft Issues Urgent Security Alert Over Cyberattacks Targeting Global Agencies And Businesses. An urgent security alert has been issued by Microsoft regarding cyberattacks exploiting a previously unknown vulnerability. These attacks are targeting global agencies and businesses, highlighting the critical need for immediate action to secure systems. Organizations are encouraged to stay vigilant and implement recommended security measures to prevent breaches. Source
5. Critical Unpatched SharePoint Zero-Day Actively Exploited, Breaches 75+ Global Organizations. A critical unpatched vulnerability in Microsoft SharePoint Server is being actively exploited, affecting over 75 global organizations. This zero-day flaw allows attackers to breach systems, emphasizing the urgency for organizations to apply available patches and enhance their cybersecurity defenses. The widespread impact of this vulnerability underscores the importance of proactive security measures. Source

Vulnerabilities & Patches

1. Microsoft Issues Urgent Patch for SharePoint Servers: Microsoft has released an emergency patch for a critical remote code execution vulnerability (CVE-2025-53770) affecting on-premise SharePoint servers. This flaw has been actively exploited in the wild, impacting over 85 servers. Users are urged to apply the patch immediately to mitigate potential risks. Source: Madhyamam Online
2. New Zero-Day Vulnerability in Microsoft SharePoint: A new zero-day vulnerability (CVE-2025-53770) in Microsoft SharePoint Server is being actively exploited, with no patch currently available. This vulnerability, which allows remote code execution, has been rated 9.8/10 on the CVSS scale, highlighting its critical nature. Organizations are advised to monitor updates from Microsoft closely. Source: CyberInsider
3. Microsoft SharePoint Zero-Day Exploited in RCE Attacks: A critical zero-day vulnerability in Microsoft SharePoint, tracked as CVE-2025-53770, has been actively exploited since at least July 18th. This vulnerability allows attackers to execute arbitrary code remotely, posing a significant threat to affected systems. Microsoft is working on a patch, and users are advised to implement workarounds in the meantime. Source: BleepingComputer
4. SharePoint Under Attack: Microsoft Warns of Zero-Day Exploited in the Wild: Microsoft has issued a warning to SharePoint Server users about a vulnerability (CVE-2025-53770) that is being exploited in the wild. With a CVSS score of 9.8, this vulnerability poses a severe risk, and users are encouraged to stay updated with Microsoft's security advisories. Source: SecurityWeek
5. Microsoft Releases Emergency Patches for SharePoint RCE Flaws: Microsoft has released emergency security updates for two zero-day vulnerabilities in SharePoint, tracked as CVE-2025-53770 and CVE-2025-53771. These vulnerabilities have been exploited in attacks, and users are strongly advised to apply the patches to protect their systems. Source: BleepingComputer

Podcasts

1. Cybersecurity in the Age of Quantum Computing: As quantum computing edges closer to reality, its potential impact on cybersecurity is becoming a hot topic. This podcast explores how quantum technology could both threaten and enhance current security protocols. Experts discuss the need for quantum-resistant algorithms and the future of encryption. Source: Cybersecurity Podcast.
2. Decoding the Cybersecurity Skills Gap: This podcast delves into the growing skills gap in the cybersecurity industry, examining the challenges and opportunities it presents. Industry leaders share insights on how to attract and retain talent, and the role of education and training in bridging this gap. Source: The CyberWire.
3. Blockchain's Role in Cybersecurity: With blockchain technology gaining traction, this podcast investigates its potential to revolutionize cybersecurity. Discussions include how blockchain can enhance data integrity, transparency, and trust in digital transactions. The episode also covers real-world applications and future prospects. Source: Blockchain Podcast.
4. Inside the World of Ethical Hacking: This podcast offers a deep dive into the world of ethical hacking, featuring interviews with top ethical hackers. It covers the techniques used to identify vulnerabilities and the ethical considerations involved. Listeners gain insights into how ethical hacking contributes to stronger security systems. Source: Ethical Hacking Podcast.
5. Cybersecurity and the Internet of Things (IoT): As IoT devices proliferate, this podcast examines the unique security challenges they present. Experts discuss strategies for securing IoT ecosystems and the importance of building security into devices from the ground up. The episode highlights case studies and future trends in IoT security. Source: IoT Security Podcast.

Final Words

As we wrap up today's edition of ONSEC Cyber Daily, it's clear that the digital landscape is as dynamic as ever, with Microsoft at the forefront of a relentless cyber battle. From widespread attacks on server software to critical vulnerabilities in SharePoint, the urgency for robust cybersecurity measures has never been more apparent. These incidents serve as a stark reminder of the importance of staying informed and vigilant in the face of evolving threats. We hope today's insights have equipped you with the knowledge to better protect your digital assets. Remember, cybersecurity is a collective effort, and sharing information is a powerful tool in our defense arsenal. If you found this newsletter valuable, please share it with your friends and colleagues. Together, we can build a more secure digital world. Stay safe, stay informed, and see you in the next edition of ONSEC Cyber Daily!

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ONSEC.io | 1,839 followers on LinkedIn. Information security audits and penetration testing by a team of experts with an average experience of more than 7 years | ONSEC.io - is a penetration testing & in-depth security audit company with more than 13 years of experience on the market. Our team has already helped more than 300 companies be aware about possible system's vulnerabilities, including Republic, DMarket, LegionFarm, Parallels, Xsolla, Acronis, Manyсhat, Global Fashion Group and others. Our main goal is to increase the customer security level by finding and fixing security issues as well as improve security awareness inside the company, including developers, DevOps, and other teams to build a sustainable engineering culture with security knowledge.

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