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Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense Software TCP DNS Denial of Service Vulnerability

Cisco disclosed a TCP DNS flaw in ASA and FTD firewall software letting unauthenticated remote attackers trigger device reloads and denial of service.

A logic error in the DNS over TCP implementation of Cisco Secure Firewall ASA and FTD software mishandles buffer-size tracking when parsing DNS queries. An unauthenticated, remote attacker can send a crafted reply to a DNS query sent from the targeted device, causing the TCP DNS response handler to restart and the device to reload. The result is a denial of service condition on affected firewalls.

Critical Cisco FMC Flaws Actively Exploited to Gain Root Access and Deploy Malware

Threat actors actively exploit Cisco FMC CVE-2026-20079 (CVSS 10.0) for root access, with clusters linked to Sandworm and Qilin ransomware.

Cisco Talos warns of active exploitation of CVE-2026-20079, a CVSS 10.0 authentication bypass in Cisco Secure Firewall Management Center allowing unauthenticated root-level code execution, and CVE-2026-20316 (CVSS 5.3), which permits login via a low-privileged static account for privilege escalation. Hotfixes are available now, with a broader hardening release planned for the week of September 14. Three post-compromise activity clusters were identified: UAT-12197 deployed a home.jsp web shell and cmd.jar command executor; UAT-11823, attributed with high confidence to a Sandworm-linked APT, deployed a Netcat reverse shell and Cyclops Blink; and UAT-11988 showed Qilin ransomware tactics including Active Directory enumeration and credential theft before deploying Qilin ransomware.

GBHackersupdated · 2d agofirst · 5d agoExploit / PoC in the wild 11 sourcesCVE-2026-20079CVE-2026-20316

Advanced Dns Security

Palo Alto Networks Unit 42 hosts a product archive page for its Advanced DNS Security DNS-layer threat prevention service.

The page is a product category archive on the Unit 42 blog with no article text available. Advanced DNS Security is Palo Alto Networks' DNS-layer threat prevention offering. No research findings, incidents, or vulnerabilities are described.

Palo Alto Unit 42 · 8d agoIndustry 6 sources

Your DNS Is Hiding in HTTPS — This Is Why It Matters

Akamai argues that unmanaged DNS over HTTPS (DoH) creates enterprise visibility gaps and advocates controlled DoH strategies to restore DNS monitoring.

Akamai published a blog post arguing that unmanaged DNS over HTTPS encrypts DNS queries outside enterprise visibility, creating security monitoring gaps. The post advocates a controlled DoH strategy that restores DNS visibility for defenders while preserving user privacy. No specific incidents, vulnerabilities, or products are cited in the advisory-style piece.

Akamai Blog · 14d agoIndustry

Six new dnsmasq vulnerabilities open the door to DNS cache poisoning, local root

Six dnsmasq flaws enable DNS cache poisoning, DoS, memory leaks, and local root code execution; fixes ship in version 2.92rel2.

Researchers disclosed six dnsmasq vulnerabilities spanning memory safety and input validation, including heap buffer overflows in extract_name() and extract_addresses(), DNSSEC infinite-loop and out-of-bounds read flaws, and a DHCPv6 out-of-bounds write allowing local root code execution. Exploitation paths include DNS cache poisoning, bypassing security controls, remote denial of service, and local privilege escalation. Maintainers released version 2.92rel2 with fixes, and a stable 2.93 release is expected within weeks.

Hacking Public Wi-Fi DNS to Steal Credentials

Attackers can hijack public Wi-Fi DNS to redirect users to credential-stealing fake login pages; commenters debate HTTPS limits and mitigations like encrypted DNS.

The discussion examines how an attacker controlling DNS on shared or public Wi-Fi networks can redirect requests for legitimate services to attacker-controlled servers to steal credentials. Commenters analyze whether HTTPS and certificates mitigate the attack, noting attackers often rely on HTTP or browser trust quirks. Suggested defenses include encrypted DNS (DoH), DNSSEC, and travel routers running OpenWRT. No specific campaign, victims, or indicators are provided.

Schneier on Security · Aug 17, 2026Research1

Automatically Detecting DNS Hijacking in Passive DNS

Unit 42's machine learning pipeline detected 6,729 DNS hijacking events between March and September 2024, hitting political parties, ISPs, and universities.

Unit 42 processes roughly 167 million new DNS records daily and applies a machine learning model using 74 features over 169 TB of passive DNS and geolocation data to flag hijacked domains. From March to September 2024 the pipeline screened over 29 billion records and classified 6,729 as DNS hijacking, averaging 38 detections per day; a new model detects hijacks in customer traffic within about 10 minutes. Notable cases include a Hungarian political party's hijacked domain, defacement of a large utility company and ISP, and university and research center domains repurposed for illicit gambling. DNS hijacking typically relies on stolen registrar or DNS provider credentials or cache poisoning, enabling MitM attacks, phishing, drive-by downloads, and scams.

Palo Alto Unit 42 · Aug 17, 2026Research in the wild

Almost Half of Malware Samples Communicate Direct to IP

Unit 42 analysis of 4 million malware reports finds 45% of C2-active samples connect directly to hard-coded IPs, bypassing DNS defenses.

Palo Alto Unit 42 analyzed over 4 million Advanced WildFire dynamic analysis reports and found that 45.32% of malware samples with C2 activity made at least one direct-to-IP connection, accounting for 23.17% of all C2 connection attempts. The firm proposes zero trust IP (ZT-IP), an enforcement approach that verifies whether outbound destinations were ever sanctioned by a DNS response. ZT-IP analysis surfaced Phorpiex ransomware droppers fetching payloads directly from C2 IPs, a persistent data exfiltration campaign using an obfuscated \GET protocol, and Mozi P2P botnet payloads delivered to IoT devices without DNS. Only 1% of benign samples connected directly to untrusted IP addresses.

Palo Alto Unit 42 · Aug 17, 2026Research

Autoencoder Is All You Need: Profiling and Detecting Malicious DNS Traffic

Palo Alto Unit 42 details an autoencoder-based method that profiles DNS traffic to detect C2 and malicious domains, blocking ~374,000 malicious DNS requests daily.

Unit 42 built an RNN-based autoencoder that compresses DNS traffic time series into fixed-dimensional 'DNS profiles' for each domain and device. Downstream classification, clustering, and anomaly detection modules flag suspicious domains, capturing 170 emerging suspicious domains in May 2024. Signatures block roughly 374,000 malicious DNS requests daily and run in the Advanced DNS Security service, with detections shared to Advanced URL Filtering. Case studies link DNS traffic patterns to C2 beaconing, dynamic DNS abuse, and DNS tunneling for data exfiltration.

Palo Alto Unit 42 · Aug 17, 2026Research

[remote] D-Link DNS_340L - OS Command Injection

An OS command injection exploit was published for the D-Link DNS-340L NAS, a flaw relevant to exposed network storage devices.

Exploit-DB published exploit #52643 for the D-Link DNS-340L network-attached storage device. The vulnerability is an OS command injection, which could allow arbitrary command execution on affected devices. The disclosure text does not report exploitation in the wild.

Exploit-DB · Aug 17, 2026Exploit / PoC

ZDI-26-584: dnsmasq DNSSEC NSEC/NSEC3 Type Bitmap Processing Infinite Loop Denial-of-Service Vulnerability

ZDI disclosed an unauthenticated infinite-loop denial-of-service flaw (CVE-2026-4890) in dnsmasq DNSSEC NSEC/NSEC3 bitmap processing.

The Zero Day Initiative published ZDI-26-584 describing an infinite loop in dnsmasq's processing of DNSSEC NSEC/NSEC3 type bitmaps. Remote unauthenticated attackers can trigger a denial-of-service condition on affected installations. ZDI assigned a CVSS score of 7.5 and the identifier CVE-2026-4890.

ZDI Published Advisories · Aug 13, 2026VulnerabilityCVE-2026-4890

Cavern C2 Uses DNS and Google Apps Script to Blend Into Legitimate Traffic

Kaspersky details Iranian Cavern Manticore's expanded C2 framework using DNS and Google Apps Script, plus APT42's TAMECAT spyware in nuclear-sector phishing.

Kaspersky reported new components in the Cavern (Cav3rn) C2 framework, used by Iranian MOIS-affiliated Cavern Manticore (with overlaps to MuddyWater and OilRig's Lyceum) against Israeli entities, monitored since December 2025. The new GoogleService.dll module performs DNS A-record queries to choose between direct HTTPS and a Google Apps Script relay per transaction, with the DNS infrastructure able to rotate the Google deployment ID; Kaspersky also found an inter-component broker (rnp.dll) and linked the framework's plugin-based pivot to late April 2026. Separately, Group-IB and Kaspersky detailed HOLLOWGRAPH, a .NET NativeAOT DLL first seen in the wild June 7, 2026, that uses Microsoft 365 calendar events via the Graph API as two-way dead drops dated May 13, 2050, with DNS tunneling refreshing Entra ID credentials. DarkAtlas also reported APT42's TAMECAT modular surveillance framework delivered via LNK masquerading as PDFs in spear-phishing targeting the nuclear energy sector in April-May 2026, with the group using generative AI to accelerate operations.

The Hacker News · 29d agoThreat actor

Next.js 16.4.0-canary.13 Image Optimizer DNS Rebinding TOCTOU SSRF Still Exists

Next.js 16.4.0-canary.13 Image Optimizer retains a DNS rebinding TOCTOU SSRF in fetchExternalImage() allowing requests to private network resources.

Next.js 16.4.0-canary.13 contains a DNS rebinding time-of-check-to-time-of-use Server-Side Request Forgery vulnerability in the Image Optimizer's fetchExternalImage() function. The code resolves the supplied hostname and checks the resulting addresses with isPrivateIp(), but a TOCTOU gap between resolution and the actual fetch allows an attacker-controlled DNS record to change and reach private network resources.

Full Disclosure · 12d agoVulnerability

USN-8742-1: Netty vulnerability

Ubuntu issues USN-8742-1 fixing a Netty DNS cache poisoning flaw caused by improper NS record bailiwick validation.

Ubuntu Security Notice USN-8742-1 addresses a vulnerability in the Netty framework in which NS records are incorrectly validated for bailiwick. An attacker could potentially exploit this to facilitate DNS cache poisoning attacks. Updated packages are available for supported Ubuntu releases.

Ubuntu Security Noticesupdated · 6h agofirst · 6d agoAdvisory 12 sources

xHunt Campaign: New PowerShell Backdoor Blocked Through DNS Tunnel Detection

xHunt's new CASHY200 PowerShell backdoor used DNS tunneling for C2; DNS security blocked beaconing at a Kuwait organization in September 2019.

Unit 42 describes CASHY200, a new PowerShell-based backdoor tied to the xHunt campaign that communicates with its C2 server windows64x[.]com via DNS tunneling, parsing commands from DNS answers. In September 2019, a Kuwait-based organization's DNS security service blocked the beaconing minutes after detection, cutting off adversary access. Samples dating to May and June 2018 and open source collection suggest the tool was used against Kuwait government organizations from spring 2018 through 2019, with malicious Word documents observed installing CASHY200 payloads configured with C2 domains such as firewallsupports[.]com and winx64-microsoft[.]com. The tool's name derives from identifiers stored under the registry key HKCU\Software\Microsoft\Cashe and the command value 200.

Palo Alto Unit 42 · Aug 17, 2026Threat actor

A rant about phishing: It's not the user's fault (and not DNS either)

Opinion piece argues multi-domain login redirects make legitimate flows indistinguishable from phishing, urging organizations to standardize on one recognizable root domain.

The author shows a real-world login flow that chains through numerous third-party domains (identity providers, cloud auth endpoints, OAuth APIs, 2FA pages), none on the company's own domain, so credentials and 2FA prompts are trivially impersonable. The piece argues URLs are inherently confusing because the security-relevant second-level domain sits mid-string, and that users trained to ignore URLs cannot distinguish legitimate pages from scams. It proposes RFC 2119-style requirements: single recognizable root domain, internal services on its subdomains, emailed or SMS links on that domain, and local redirects instead of third-party hosted pages.

Lobsters · security · 6d agoPhishing & fraud

New Phishing Attacks Use Trusted Email Infrastructure and URL Cloaking to Bypass Security Tools

Virus Bulletin Q3 2026 report details phishing using DKIM-aligned senders, Amazon SES delivery, and real-time URL cloaking to evade email security and scanners.

Virus Bulletin's Q3 2026 testing found phishing campaigns delivered through trusted infrastructure like Amazon SES with DKIM-aligned sender domains. Samples included a German overdue-invoice lure redirecting to OpenSea crypto fraud and a Romanian BCR-branded PSD2 banking credential-theft campaign. Cloaking pages used hidden iframes, browser fingerprinting, and time-zone checks to show different content to scanners versus victims. Defenders are urged to inspect full redirect chains rather than attachments or initial URLs alone.

Cyber Security Newsupdated · 1d agofirst · 1d agoPhishing & fraud in the wild 2 sources

Active exploitation of Cisco Secure Firewall Management Center vulnerabilities

Cisco Talos reports in-the-wild exploitation of critical FMC flaw CVE-2026-20079 by three clusters including a Sandworm-linked APT and Qilin ransomware affiliates.

Cisco Talos is tracking active exploitation of CVE-2026-20079 (CVSS 10.0), an authentication bypass in Cisco Secure Firewall Management Center that lets unauthenticated remote attackers execute scripts and obtain root access, and CVE-2026-20316 (CVSS 5.3), which permits low-privileged logins and can be chained for privilege escalation. Talos identified three post-compromise clusters: UAT-12197 deploying JSP web shells and a JAR command executor for credential theft; UAT-11823, an APT overlapping with Sandworm, deploying a Netcat reverse shell and Cyclops Blink malware; and UAT-11988, assessed as a ransomware operator with TTPs consistent with Qilin affiliates. Hotfixes are available, with a comprehensive hardening release due the week of September 14, 2026.

[dos] LuCI DHCPv6 - Lease Hostname Stored Cross-Site Scripting

Stored cross-site scripting in OpenWrt LuCI via malicious DHCPv6 lease hostnames allows router interface attacks.

Exploit-DB entry 52637 describes a stored cross-site scripting vulnerability in LuCI, the OpenWrt web administration interface. A attacker on the local network can set a malicious hostname that gets stored in DHCPv6 lease data and rendered unsafely in the LuCI UI. When an administrator views the lease status page, the injected script executes in the router's management context.

Exploit-DB · Aug 11, 2026Exploit / PoC

The purpose of DNS is to spread scams

Interisle data cited by Terence Eden shows 8.5 million of 85 million new 2025 gTLD registrations blocklisted, implying a 10-20% scam domain abuse rate.

Terence Eden highlights statistics from an Interisle report on Domain Name System abuse. Of 85 million new gTLD registrations in 2025, 8.5 million were added to blocklists by May 2025, suggesting a 10% abuse floor that is likely closer to 20%. Eden calls the roughly one-in-five scam rate for newly registered gTLD domains a crisis and notes ICANN has discussed the problem for years.

Simon Willison · 10d agoPhishing & fraud

ISC has disclosed fourteen vulnerabilities in BIND 9 (CVE-2026-19033, CVE-2026-19662, CVE-2026-19666, CVE-2026-19667, CVE-2026-19668, CVE-2026-19941, CVE-2026-75029, CVE-2026-76163, CVE-2026-77119, CVE-2026-77692, CVE-2026-78301, CVE-2026-80274, CVE-2026-81563, CVE-2026-81736)

ISC discloses fourteen vulnerabilities in BIND 9 DNS software, including a use-after-free, with fixes now available.

On September 16, 2026, Internet Systems Consortium disclosed fourteen vulnerabilities affecting BIND 9, listing CVE-2026-19033, CVE-2026-19662, CVE-2026-19666 (use-after-free), CVE-2026-19667, CVE-2026-19668, CVE-2026-19941, CVE-2026-75029, CVE-2026-76163, CVE-2026-77119, CVE-2026-77692, CVE-2026-78301, CVE-2026-80274, CVE-2026-81563, and CVE-2026-81736. Details and fixes are published in the ISC knowledge base. No active exploitation is reported in the announcement.

The GNU C Library security advisory update for 2026-09-10

glibc advisory GLIBC-SA-2026-0016: nscd can crash from a stack overflow when an untrusted DNS server returns oversized responses.

A new GNU C Library advisory (GLIBC-SA-2026-0016) describes a stack overflow in the nscd service caused by unbounded alloca use. glibc 2.3.4 and newer may crash when a malicious DNS server returns an oversized response, resulting in degraded DNS resolution. Exploitation requires nscd to be enabled and the system to be using an untrusted DNS server. The advisory was posted to oss-security by glibc maintainer Siddhesh Poyarekar.

oss-securityupdated · 1d agofirst · 5d agoVulnerability 2 sources2

cPanel LiteSpeed Web Server Vulnerability Allows Shared Server Users to Gain Root-Level Access

Critical LiteSpeed Enterprise flaw fixed in 6.3.7 lets low-privilege shared-hosting users escalate to root and bypass CageFS.

cPanel issued an urgent advisory for a critical privilege escalation in LiteSpeed Web Server Enterprise versions before 6.3.7, allowing a low-privilege shared-hosting account to gain root-level server control and bypass tenant isolation controls including CloudLinux CageFS. Root access would let attackers access other hosted sites, steal databases and credentials, deploy phishing pages, and install backdoors. Administrators are urged to upgrade to 6.3.7 immediately via lsup.sh and to review privileged account activity, cron jobs, SSH keys, and system binaries; no CVE identifier was published.

Cyber Security News · 1d agoVulnerability

Hackers Steal Active Directory Password Hashes Without Attacking Domain Controllers Directly

Attackers use the DCSync technique to impersonate domain controllers and harvest AD password hashes and Kerberos keys without directly compromising domain controllers, Trellix warns.

Per Trellix, threat actors increasingly abuse Active Directory replication via DCSync, using privileged credentials to invoke DRSGetNCChanges and retrieve NTLM password hashes and Kerberos key material without running code on domain controllers. Capturing the krbtgt account hash enables forging Golden Tickets for persistent, highly privileged domain access. Because malicious replication traffic mimics legitimate DRS/RPC activity, defenders should monitor Windows Security Event ID 4662, restrict replication permissions, and investigate replication requests from non-domain-controller systems.

GBHackers · 6d agoResearch in the wild 2 sources2

Cisco ASA and FTD DoS Vulnerability Exploited in the Wild (CVE-2026-20349)

Cisco patched actively exploited high-severity flaw CVE-2026-20349 in ASA and FTD SSL VPN services, allowing unauthenticated remote denial-of-service attacks.

Cisco released a security advisory addressing CVE-2026-20349, a high-severity vulnerability in the Remote Access SSL VPN service of Cisco Secure Firewall ASA and FTD Software. Successful exploitation by an unauthenticated remote attacker can cause affected devices to crash or reload, causing denial of service. The vulnerability is being exploited in the wild, and patches are available; organizations with internet-exposed ASA/FTD VPN endpoints should prioritize updating.

Qualys ThreatPROTECT · Aug 13, 2026Exploit / PoC in the wildCVE-2026-20349

1.1.1.1 now supports post-quantum DNSSEC, all 2,420 bytes of it

Cloudflare's 1.1.1.1 resolver now validates post-quantum DNSSEC signatures using ML-DSA-44, a 2,420-byte NIST algorithm, preparing DNS for post-quantum migration by 2029.

Cloudflare enabled 1.1.1.1 to validate DNSSEC signatures using ML-DSA-44 (algorithm 18), a NIST-standardized post-quantum signature with 1,312-byte public keys and 2,420-byte signatures, roughly 38x larger than ECDSA P-256. The large signatures exceed common DNS-over-UDP limits, forcing fallback to TCP and creating downgrade risks while conventional algorithms must be published alongside. Cloudflare cites the risk of a quantum computer breaking RSA/ECDSA signatures by 2030 and plans full post-quantum security by 2029.

Cloudflare Blog · 6d agoTools1