DirtyClone: A Linux Privilege Escalation That Leaves No Trace on Disk

Security Affairs

Carding service Jerry’s Store leak exposes 345,000 stolen payment cards Anthropic launches Claude Security to counter rapid AI-Powered exploits SonicWall patches three SonicOS flaws in Gen 6, 7 and 8 firewalls. Patch them now Copy Fail: New Linux bug enables Root via page‑cache corruption Agent’s claims on WhatsApp access spark security concerns Meta accused of violating DSA by failing to safeguard minors Large-scale Roblox hacking operation shut down by Ukrainian authorities CVE-2026-42208: LiteLLM bug exploited 36 hours after its disclosure Internet censorship index reveals Russia’s lead and widespread content blocking All supported cPanel versions hit by critical auth bug, now patched U.S. CISA adds Microsoft Windows Shell and ConnectWise ScreenConnect flaws to its Known Exploited Vulnerabilities catalog ShinyHunters exploit Anodot incident to target Vimeo CVE-2026-3854 GitHub flaw enables remote code execution Signal Phishing Campaign Targets German Officials in Suspected Russian Operation Microsoft fixes Entra ID flaw enabling privilege escalation New Android spyware Morpheus linked to Italian surveillance firm NCSC launches SilentGlass, a plug-in device to secure HDMI and DisplayPort links Medtronic discloses security incident after ShinyHunters claimed theft of 9M+ records Chinese spy posed as researcher in spear-phishing campaign targeting NASA to steal defense software LINKEDIN BROWSERGATE Firefox bug CVE-2026-6770 enabled cross-site tracking and Tor fingerprinting Fast16: Pre-Stuxnet malware that targeted precision engineering software Italy moves to extradite Chinese national to the U.S. over hacking charges U.S. utility giant Itron discloses a security breach Critical bug in CrowdStrike LogScale let attackers access files GopherWhisper: new China-linked APT targets Mongolia with Go-based malware SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 94 Trigona ransomware adopts custom tool to steal data and evade detection Security Affairs newsletter Round 574 by Pierluigi Paganini – INTERNATIONAL EDITION U.S. CISA adds SimpleHelp, Samsung, and D-Link flaws to its Known Exploited Vulnerabilities catalog Over 400,000 sites at risk as hackers exploit Breeze Cache plugin flaw (CVE-2026-3844) CISA reports persistent FIRESTARTER backdoor on Cisco ASA device in federal network 12-year-old Pack2TheRoot bug lets Linux users gain root privileges Signal phishing campaign targets Germany’s Bundestag President Julia Klöckner China-linked threat actors use consumer device botnets to evade detection, warn UK and partners Luxury cosmetics giant Rituals discloses data breach impacting member personal details iOS Flaw Let Deleted Notifications Linger, Apple Issues Fix RAMP Uncovered: Anatomy of Russia’s Ransomware Marketplace U.S. CISA adds a flaw in Microsoft Defender to its Known Exploited Vulnerabilities catalog Microsoft Graph API misused by new GoGra Linux malware for hidden communication DDoS wave continues as Mastodon hit after Bluesky incident Mirai Botnet exploits CVE-2025-29635 to target legacy D-Link routers Microsoft out-of-band updates fixed critical ASP.NET Core privilege escalation flaw Critical BRIDGE:BREAK flaws impact Lantronix and Silex Technology converters Venezuela energy sector targeted by highly destructive Lotus wiper Ransomware negotiator caught secretly assisting BlackCat extortion scheme North Korea’s Lazarus APT stole $290M from Kelp DAO The US NSA is using Anthropic’s Claude Mythos despite supply chain risk U.S. CISA adds Cisco Catalyst, Kentico Xperience, PaperCut NG/MF, Synacor ZCS, Quest KACE SMA, and JetBrains TeamCity flaws to its Known Exploited Vulnerabilities catalog Bluesky hit by 24-hour DDoS attack as pro-Iran group claims responsibility France’s ANTS ID System website hit by cyberattack, possible data breach Scattered Spider member Tyler Buchanan pleads guilty to major crypto theft CVE-2023-33538 under attack for a year, but exploitation still unsuccessful Third-party AI hack triggers Vercel breach, internal environments accessed AI Model Claude Opus turns bugs into exploits for just $2,283 Cyber attacks fuel surge in cargo theft across logistics industry SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 93 Security Affairs newsletter Round 573 by Pierluigi Paganini – INTERNATIONAL EDITION Hidden VMs: how hackers leverage QEMU to stealthily steal data and spread malware Nexcorium Mirai variant exploits TBK DVR flaw to launch DDoS attacks Microsoft Defender under attack as three zero-days, two of them still unpatched, enable elevated access Kyrgyzstan-based crypto exchange Grinex shuts down after $13.7M cyber heist, blames Western Intelligence DraftKings hacker sentenced to prison, ordered to pay $1.4 Million Operation PowerOFF: 53 DDoS domains seized and 3 Million criminal accounts uncovered Inside ZionSiphon: politically driven malware aims at Israeli water systems U.S. CISA adds a flaw in Apache ActiveMQ to its Known Exploited Vulnerabilities catalog Cisco fixed four critical flaws in Identity Services and Webex Cookeville Regional Medical Center hospital data breach impacts 337,917 people AI platform n8n abused for stealthy phishing and malware delivery From clinics to government: UAC-0247 expands cyber campaign across Ukraine Sweden reports cyberattack attempt on heating plant amid rising energy threats CVE-2026-33032: severe nginx-ui bug grants unauthenticated server access U.S. CISA adds Microsoft SharePoint Server, and Microsoft Office Excel flaws to its Known Exploited Vulnerabilities catalog Mirax malware campaign hits 220K accounts, enables full remote control PHP Composer flaws enable remote command execution via Perforce VCS Microsoft Patch Tuesday for April 2026 fixed actively exploited SharePoint zero-day Personal data of 1 million gym members compromised in Basic-Fit security incident US, UK and Canada disrupt $45M crypto theft in Operation Atlantic ShinyHunters claim the hack of Rockstar Games breach and started leaking data Attackers target unpatched ShowDoc servers via CVE-2025-0520 U.S. CISA adds Adobe, Fortinet, Microsoft Exchange Server, and Microsoft Windows flaws to its Known Exploited Vulnerabilities catalog Citizen Lab: Webloc tracked 500M devices for global law enforcement Iran-linked group Handala claims to have breached three major UAE organizations Adobe fixes actively exploited Acrobat Reader flaw CVE-2026-34621 Hackers claim control over Venice San Marco anti-flood pumps SECURITY AFFAIRS MALWARE NEWSLETTER ROUND 92 Security Affairs newsletter Round 572 by Pierluigi Paganini – INTERNATIONAL EDITION Censys finds 5,219 devices exposed to attacks by Iranian APTs, majority in U.S. GlassWorm evolves with Zig dropper to infect multiple developer tools CVE-2026-39987: Marimo RCE exploited in hours after disclosure Ransomware attack on ChipSoft knocks EHR services offline across hospitals in the Netherlands and Belgium UAT-10362 linked to LucidRook attacks targeting Taiwan-based institutions EngageLab SDK flaw opens door to private data on 50M Android devices Bitcoin Depot hack leads to $3.6M Bitcoin theft via stolen credentials Eurail data breach impacted 308,777 people Malicious PDF reveals active Adobe Reader zero-day in the wild Masjesu botnet targets IoT devices while evading high-profile networks The alleged breach of China’s National Supercomputing Center can have serious geopolitical consequences Internet-Exposed ICS Devices Raise Alarm for Critical Sectors U.S. CISA adds a flaw in Ivanti EPMM to its Known Exploited Vulnerabilities catalog

https://www.facebook.com/sec.affairs · 2026-06-27 · via Security Affairs

DirtyClone: a Linux kernel privilege escalation that silently rewrites executables in memory, leaving no disk trace. Patch now.

JFrog Security Research published a working exploit walkthrough on June 25 for CVE-2026-43503 (CVSS score of 8.8), a Linux kernel privilege escalation they call DirtyClone. It’s the fourth vulnerability in the DirtyFrag family, all sharing the same root failure: file-backed memory gets treated as packet data, and an in-place network operation writes where it should have copied. CVSSIf your kernel doesn’t have the May 21 mainline patch, update now.

“The severity of this issue is significant because it allows any unprivileged local user to gain root access (LPE) by manipulating the Linux page cache.” reads the report published by JFrog. “The attack is silent, leaves no kernel logs or audit traces, and bypasses common on-disk integrity monitoring tools.”

The attacker loads a privileged binary like /usr/bin/su into memory, wires those pages into a network packet, and forces the kernel to clone it through a loopback IPsec tunnel they control. The decryption step overwrites the binary’s authentication logic with attacker-chosen bytes, and the next run of su hands over root — while the file on disk stays untouched.

The exploit requires CAP_NET_ADMIN to configure the IPsec environment. On Debian and Fedora that capability is reachable by any local user through unprivileged user namespaces, which are enabled by default.

“The attacker begins by creating a fresh network namespace:

unshare -Urn

This provides network administrative capabilities inside the namespace.” continues the report. “While capabilities are namespaced, page cache is shared at the host level, so if file-backed pages are modified through shared mappings, the effects may propagate to other processes using those pages.”

Ubuntu 24.04 and later restrict namespace creation via AppArmor, blocking the default exploit path, but every other distribution with default namespace configurations is exposed.

The DirtyFrag family now has four members. Copy Fail (CVE-2026-31431) arrived in late April. DirtyFrag (CVE-2026-43284 and CVE-2026-43500) followed on May 7. Fragnesia (CVE-2026-46300) appeared on May 13, bypassing the DirtyFrag patch through a flag-dropping bug in skb_try_coalesce().

“DirtyFrag is a family of Linux kernel memory corruption vulnerabilities in the core networking stack affecting how socket buffers (skb) reference shared page-cache memory, which are subsequently weaponized through in-place cryptographic transformations in subsystems like XFRM/IPsec or RxRPC.” continues the report. “Despite targeting different packet cloning or forwarding paths, variants like DirtyFrag, Fragnesia, and DirtyClone all rely on a shared technique: tricking the kernel into treating read-only, file-backed page cache memory as writable network buffers.”

Each patch closed one code path and left others open. The underlying contract, that every function moving socket buffer fragments must preserve the shared-frag flag, every time, was never fully enforced across the codebase.

The original DirtyFrag researcher Hyunwoo Kim submitted a broader multi-site patch on May 16 covering the remaining fragment-transfer helpers. JFrog independently rediscovered one of the affected functions on May 19, built a working exploit, and reported it. The combined fix merged on May 21, CVE-2026-43503 was published on May 23, and Linux v7.1-rc5 shipped on May 24 as the first fixed release. Ubuntu, Debian, and SUSE have published advisories; Red Hat has a Bugzilla tracking entry.

If patching today isn’t an option, two workarounds reduce the attack surface. Setting kernel.unprivileged_userns_clone=0 on Debian and Ubuntu blocks the namespace-based path to CAP_NET_ADMIN. Blacklisting the esp4, esp6, and rxrpc kernel modules removes the in-place decryption primitives the exploit needs, though that breaks IPsec and AFS. Neither is a fix. The DirtyFrag class probably isn’t finished: any fragment-transfer function that drops the shared-frag flag along the way is a potential new variant, and auditing every such path in the kernel networking stack is a large and unfinished job.

JFrog published a Proof Of Concept video for the exploitation of the flaw.

Follow me on Twitter: @securityaffairs and Facebook and Mastodon

Pierluigi Paganini

(SecurityAffairs – hacking, Linux)

此内容由惯性聚合(RSS阅读器)自动聚合整理，仅供阅读参考。原文来自 — 版权归原作者所有。

推荐订阅源

Security Affairs

DirtyClone: a Linux kernel privilege escalation that silently rewrites executables in memory, leaving no disk trace. Patch now.