Maximum Severity Cisco SD-WAN Bug Exploited in the Wild

Maximum Severity Cisco SD-WAN Bug Exploited in the Wild

Newsletter Sign-UpNewsletter Sign-UpCybersecurity TopicsRelated TopicsApplication SecurityCybersecurity CareersCloud SecurityCyber RiskCyberattacks & Data BreachesCybersecurity AnalyticsCybersecurity OperationsData PrivacyEndpoint SecurityICS/OT SecurityIdentity & Access Mgmt SecurityInsider ThreatsIoTMobile SecurityPerimeterPhysical SecurityRemote WorkforceThreat IntelligenceVulnerabilities & ThreatsRecent in Cybersecurity TopicsEndpoint SecurityChina's Webworm Uses Discord, Microsoft Graphs to Hack EU GovernmentsChina's Webworm Uses Discord, Microsoft Graphs to Hack EU GovernmentsbyAlexander CulafiMay 22, 20264 Min ReadApplication SecurityGitHub Confirms Breach, 4K Internal Repos StolenGitHub Confirms Breach, 4K Internal Repos StolenbyAlexander CulafiMay 20, 20263 Min ReadWorld Related TopicsDR GlobalMiddle East & AfricaAsia PacificLatin AmericaSee AllThe EdgeDR TechnologyEventsRelated TopicsUpcoming EventsPodcastsWebinarsSEE ALLResourcesRelated TopicsResource LibraryNewslettersPodcastsReportsVideosWebinarsWhite Papers Partner PerspectivesDark Reading Resource LibraryVulnerabilities & ThreatsСloud SecurityCybersecurity OperationsPerimeterNewsMaximum Severity Cisco SD-WAN Bug Exploited in the WildThis is the second time this year a threat actor has leveraged a CVSS 10.0 vulnerability in Cisco's network control system.Nate Nelson,Contributing WriterMay 14, 20264 Min ReadSource: MTP via Alamy Stock PhotoA highly sophisticated threat actor is exploiting a critical vulnerability in Cisco Catalyst Software-Defined Wide Area Network (SD-WAN) Controllers.Rapid7 disclosed CVE-2026-20182, an authentication bypass vulnerability in Cisco's market-leading network management solution. By allowing unauthenticated attackers free rein over one of an organization's most powerful tools, it earned the highest possible 10 out of 10 score in the Common Vulnerability Scoring System (CVSS).In an updated blog post today, Rapid7 director of vulnerability intelligence Douglas McKee hammered home just how serious an issue this was. "Attackers have become very good at turning central infrastructure weaknesses into high impact operations," he warned, and for nation-states in particular, "an SD-WAN controller is a great place to do [espionage], because it lives in the middle of trust relationships most organizations rarely question." To avoid sensationalizing, McKee added, "To be fair, not every bug turns into Internet-wide exploitation overnight."Related:Microsoft Exchange Zero-Day Under Attack, No Patch AvailableIn fact, CVE-2026-20182 had been exploited overnight. In a separate publication that same day, researchers at Cisco Talos flagged that a group it tracks as UAT-8616 has already gotten to it.Hackers Leverage Critical Bugs in Cisco CatalystNot only is CVE-2026-20182 not the first vulnerability discovered in Cisco Catalyst this year, it isn't even the first authentication bypass vulnerability with a "critical" 10 score on the CVSS scale.Back in February, Cisco revealed half a dozen issues with Catalyst. The cream was CVE-2026-20127, which gave unauthenticated attackers the power to log into Cisco controllers as high-privileged users. Though Cisco characterized in-the-wild exploitation of CVE-2026-20127 as "limited," Talos researchers suggested that it was extensive, lasting at least a few years — a lifetime in cyber years. They labeled the threat cluster actor behind that exploitation "UAT-8616," calling it "highly sophisticated."Cisco patched CVE-2026-20127, threatening to derail UAT-8616's fun. The threat actor was unphased, though, as it seems to have almost immediately picked up with yet another, nearly identical vulnerability in the very same product line.The difference is really only a technicality. In February, the issue was that the Catalyst Controller and Manager weren't rigorous enough in authenticating SD-WAN components, so any hacker off the street could use a specially crafted message to impersonate a device and get in. This month, the problem is that the Controller doesn't actually verify the legitimacy of a specific type of component — a hub router, "vHub," used in cloud deployments — before authenticating it. As a consequence, and as with the February CVE before it, attackers can use this new CVE to obtain administrative privileges in targeted systems and access "NETCONF," a protocol through which they could mess with all kinds of network configurations.Related:Can Laws Stop Deepfakes? South Korea Aims to Find OutWhat Might Happen Next to Cisco's CustomersThe first time UAT-8616 exploited a Catalyst authentication bypass bug, it took advantage of its access to exploit an older vulnerability, CVE-2022-20775, and escalate from privileged to outright root access. Without spelling it out, Talos indicated that the threat actor might have been "looking to establish persistent footholds into high-value organizations including Critical Infrastructure (CI) sectors." This time around, the researchers observed the threat actor performing "similar post-compromise actions" after winning initial access, including adding SSH keys to targeted systems, modifying NETCONF configurations, and escalating to root.Little is known of UAT-8616 beyond all this, but those willing to speculate might note that the most sophisticated threat actors who abuse edge technologies, especially Cisco products, are usually Chinese. On top of that, in its latest blog, Talos wrote that UAT-8616 "overlaps with the Operational Relay Box (ORB) networks" it tracks, ORBs being most common among Chinese groups.Related:'Dirty Frag' Exploit Poised to Blow Up on Enterprise Linux DistrosOrganizations that hope to avoid UAT-8616 should implement Cisco's newly released patch for CVE-2026-20182. Otherwise, "Centralized control planes do carry higher consequences when a vulnerability occurs, because a single compromised controller can affect the entire overlay network," warns Jonah Burgess, senior security researcher at Rapid7.Despite the huge risks from vulnerabilities that seem to be coming hard and fast these days, Burgess suggests that organizations not be too dissuaded. "Centralized SD-WAN management solves real operational problems, and the architecture itself isn't the flaw," he says.Don't miss the latest Dark Reading Confidential podcast, How the Story of a USB Penetration Test Went Viral. Two decades ago Dark Reading posted its first blockbuster piece — a column by a pen tester who sprinkled rigged thumb drives around a credit union parking lot and let curious employees do the rest. This episode looks back at the history-making piece with its author, Steve Stasiukonis. Listen now!About the AuthorNate NelsonContributing WriterNate Nelson is a journalist and award-winning scriptwriter. In addition to Dark Reading he writes for Darknet Diaries, the most popular show in cybersecurity across all media.He began his career as a freelancer, ghostwriting Forbes and CNBC op-eds for executives in tech and finance. Then he transitioned to journalism at Threatpost, where he covered cybersecurity news and trends. Throughout those years he co-created a cybersecurity podcast, Malicious Life, which in its day climbed into the Top 20 technology podcasts charts on Apple Podcasts and Spotify.He holds degrees from New York University and Bard College. As a born and bred New Yorker, he enjoys a superiority complex, but is polite enough to keep it to himself.See more from Nate NelsonWant more Dark Reading stories in your Google search results?Add Us NowMore InsightsIndustry ReportsHow Organizations Are Managing Incident ResponseHow Enterprises Are Developing Secure ApplicationsInside RSAC 2026: security leaders reveal the risks redefining your defense strategyHow Enterprises Are Harnessing Emerging Technologies in CybersecurityDitch the Data Center: Understanding Flexible Cloud Infrastructure Security ManagementAccess More ResearchWebinarsBuild vs. Buy: The Hidden Cost of Building Your Own AI Security StackDefending in the Shadow Era: When the CVE Feed Goes DarkBuilding SecOps That Make the Most of Every DollarAI-Powered Cybersecurity for Resource-Constrained OrganizationsAI-Powered Credential Security: Intelligence Without ExposureMore WebinarsEditor's ChoiceThreat IntelligenceFrom Stuxnet to ChatGPT: 20 News Events That Shaped CyberFrom Stuxnet to ChatGPT: 20 News Events That Shaped CyberbyDark Reading Editorial TeamMay 6, 202631 Min ReadCyber RiskPhysical Cargo Theft Gets a Boost From CybercriminalsPhysical Cargo Theft Gets a Boost From CybercriminalsbyRobert LemosMay 4, 20265 Min ReadWant more Dark Reading stories in your Google search results?Keep up with the latest cybersecurity threats, newly discovered vulnerabilities, data breach information, and emerging trends. 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