Cisco AsyncOS Exploited, SonicWall SMA Fix, HPE OneView Patched – Cybersecurity News [December 15, 2025]

Cisco AsyncOS Exploited, SonicWall SMA Fix, HPE OneView Patched – Cybersecurity News [December 15, 2025]

Cisco AsyncOS Exploited, SonicWall SMA Fix, HPE OneView Patched – Cybersecurity News [December 15, 2025]

by DuoCircle

Cybersecurity and email security teams faced a busy week as active exploitation targeted core infrastructure and widely used platforms. Cisco warned of a critical AsyncOS zero-day affecting Secure Email appliances, while SonicWall patched an SMA 100 flaw reportedly chained for root-level takeover. HPE fixed a maximum-severity OneView RCE issue. SoundCloud also confirmed a breach exposing user emails and profile data, alongside outages, VPN blocks, and follow-on disruption. 

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Boost Email Security Using the Latest DMARC Wizard Innovations

Boost Email Security Using the Latest DMARC Wizard Innovations

 

In the current digital environment, email continues to be a crucial means of communication for companies, while also being a prime target for cybercriminals. As phishing schemes, spoofing, and domain impersonation increase, it’s essential to prioritize the protection of your email systems. This is where the new advancements in DMARC Wizard come into play — robust tools aimed at enhancing and streamlining your email authentication process. 

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SMTP Protocol Basics for IT and Cybersecurity Professionals

SMTP Protocol Basics for IT and Cybersecurity Professionals

The Simple Mail Transfer Protocol (SMTP) is the foundational communication protocol for sending electronic mail across the Internet. Developed by the Internet Network Working Group and standardized in multiple key RFCs—most notably RFC 5321—SMTP governs the process of email transmission between email clients, mail servers, and intermediary systems. As digital communication has become ubiquitous, SMTP’s importance in ensuring the reliable delivery of electronic messages cannot be overstated.

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Is p=reject the ultimate DMARC policy? 5 situations in which you should implement it

Is p=reject the ultimate DMARC policy? 5 situations in which you should implement it

Is p=reject the ultimate DMARC policy? 5 situations in which you should implement it

by DuoCircle

 

Out of the three DMARC policies—“p=none”, “p=quarantine”, and “p=reject” each serves a different purpose and provides a different level of security. But when it comes to actively blocking emails that attempt to spoof your domain, the strictest policy, “p=reject,” is the best choice.

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Microsoft 2025 Fixes, Chrome Zero-Day, Enterprise Security Flaws – Cybersecurity News [December 08, 2025]

Microsoft 2025 Fixes, Chrome Zero-Day, Enterprise Security Flaws – Cybersecurity News [December 08, 2025]

Microsoft 2025 Fixes, Chrome Zero-Day, Enterprise Security Flaws – Cybersecurity News [December 08, 2025]

by DuoCircle

 

Cyber incidents this week spanned operating systems, browsers, enterprise platforms, hardware, and developer tooling. Microsoft closed out the year patching 56 Windows flaws and three zero days, while Google rushed an emergency fix for an actively exploited Chrome bug. Fortinet, Ivanti, and SAP shipped critical updates for auth bypass and RCE risks, and new PCIe IDE weaknesses prompted firmware work from Intel and AMD. At the same time, a Gogs zero day and abused GitHub tokens highlighted ongoing threats to software supply chains.

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DKIM Authentication Explained: Securing Your Email With Verified Signatures

DKIM Authentication Explained: Securing Your Email With Verified Signatures

DomainKeys Identified Mail (DKIM) is a well-established email authentication protocol designed to help organizations defend against email spoofing, phishing attacks, and business email compromise (BEC). When implemented correctly, DKIM authentication allows the recipient’s email server to verify that a signed email has genuinely originated from the stated domain and that its message content has not been tampered with during transit.

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SPF Syntax Made Simple: Creating Accurate and Effective SPF Records

SPF Syntax Made Simple: Creating Accurate and Effective SPF Records

 

Sender Policy Framework (SPF) is a core email authentication protocol designed to enhance email security. SPF records play a crucial role in protecting domains from phishing, spoofing, and impersonation attacks by specifying which mail servers are authorized to send on behalf of a domain. When properly configured, SPF authentication significantly improves deliverability, helping emails avoid spam folders used by providers such as Gmail and Yahoo.

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