Tag Archives: EoP

June "In the Trend of VM" (#28): Linux kernel, Microsoft Defender, and Palo Alto Networks device vulnerabilities

June In the Trend of VM (#28): Linux kernel, Microsoft Defender, and Palo Alto Networks device vulnerabilities

June "In the Trend of VM" (#28): Linux kernel, Microsoft Defender, and Palo Alto Networks device vulnerabilities. Presenting the traditional monthly roundup of trending vulnerabilities according to Positive Technologies. In the previous May edition, we covered four vulnerabilities. This time, there are also four vulnerabilities associated with five CVE identifiers.

🗞 Post on Habr (rus)
🗒 Digest on the PT website (rus)

🔻 EoP - Linux Kernel "Dirty Frag" (CVE-2026-43284, CVE-2026-43500). A chain of vulnerabilities with a public exploit to obtain root access. There are signs of in-the-wild exploitation.

🔻 EoP - Linux Kernel "Fragnesia" (CVE-2026-46300). Another vulnerability for gaining root access with a public exploit.

🔻 EoP - Microsoft Defender "RedSun" (CVE-2026-41091). A privilege escalation vulnerability leading to SYSTEM-level access, with a public exploit available and indications of in-the-wild exploitation. Pay special attention to Windows server and desktop environments where Microsoft Defender is enabled but there is no Internet access for regular updates.

🔻 RCE - PAN-OS (CVE-2026-0300). An unauthenticated RCE with root privileges affecting PA-Series and VM-Series firewalls. A public exploit exists, and there are indications of in-the-wild exploitation.

🟥 The full list of trending vulnerabilities is available on the portal

June Microsoft Patch Tuesday

June Microsoft Patch Tuesday

June Microsoft Patch Tuesday. Last week I was on vacation in Veliky Novgorod, so I'm publishing this overview only now. A total of 202 vulnerabilities were addressed, approximately twice as many as in May. There are currently no vulnerabilities marked as exploited in the wild. However, there are two vulnerabilities with publicly available exploits:

🔸 RCE - HTTP.sys (CVE-2026-47291). This critical vulnerability allows remote, unauthenticated attackers to execute arbitrary code on affected systems without user interaction. However, systems using the default MaxRequestBytes registry value in the Windows HTTP stack are not affected. If needed, you can change this registry setting to protect systems while testing and deploying the patch. Microsoft's security bulletin includes instructions and a PowerShell script for this workaround.

🔸 DoS - HTTP.sys (CVE-2026-49160). The same exploit is used as for the previous RCE vulnerability.

It is also worth paying attention to vulnerabilities that Microsoft has flagged as having a publicly available exploit:

🔹 SFB - Windows BitLocker (CVE-2026-50507). A successful attacker could bypass the BitLocker Device Encryption feature on the system storage device. An attacker with physical access to the target could exploit this vulnerability to gain access to encrypted data. According to Tenable, this is the "Bitskrieg" vulnerability discovered by the researcher known as Chaotic Eclipse/Nightmare Eclipse.

🔹 SFB - Secure Boot (CVE-2026-48570). An attacker who successfully exploited this vulnerability could bypass Secure Boot. This vulnerability was reported by Alon Leviev (STORM), who is known for previous research related to BootKitty and BlackLotus.

Among the remaining vulnerabilities, the following are worth highlighting:

🔹 RCE - Windows Kernel (CVE-2026-45657). This vulnerability allows remote, unauthenticated attackers to run code with SYSTEM privileges without any user interaction. In other words, it could be used to spread automatically between systems. The issue is caused by how the Windows kernel processes TCP/IP traffic. Microsoft rated this as "Exploitation Less Likely", but security researchers and exploit developers are already analyzing the patch and trying to build an exploit. Test and deploy this patch as soon as possible.

🔹 EoP - Windows Collaborative Translation Framework (CTFMON) (CVE-2026-45586). This vulnerability affects a component used for voice and handwriting recognition. If exploited, an attacker could gain SYSTEM privileges. Microsoft rates this vulnerability as "Exploitation More Likely".

🔹 RCE - Windows Remote Desktop Client (CVE-2026-42909, CVE-2026-42913, CVE-2026-42985, CVE-2026-42992, CVE-2026-42993, CVE-2026-44799, CVE-2026-44801, CVE-2026-47289, CVE-2026-47653, CVE-2026-47654, CVE-2026-48563). Successful exploitation would require a victim to connect to an attacker-controlled server using an affected version of the Remote Desktop Client. This action could trigger a heap-based buffer overflow, resulting in remote code execution.

🔹 RCE - DHCP Client Service (CVE-2026-44815). This vulnerability allows remote, unauthenticated attackers to execute code on affected systems without user interaction. Because the DHCP client is widely enabled across Windows systems, this vulnerability presents a broad attack surface. Organizations should prioritize testing and deploying the patch for this vulnerability as soon as possible.

🗒 Full Vulristics report

About Elevation of Privilege - Linux Kernel "Fragnesia" (CVE-2026-46300) vulnerability

About Elevation of Privilege - Linux Kernel Fragnesia (CVE-2026-46300) vulnerability

About Elevation of Privilege - Linux Kernel "Fragnesia" (CVE-2026-46300) vulnerability. The vulnerability was discovered by researcher William Bowling together with the V12 team. Fragnesia belongs to the class of Dirty Frag vulnerabilities. It is an error in the ESP/XFRM subsystem, distinct from Dirty Frag, which was addressed with a separate patch. It allows achieving arbitrary byte writes into the kernel page cache of read-only files, without requiring any race condition.

🛠 Technical details and exploit code were published on May 15. The public exploit modifies the contents of /usr/bin/su in the kernel page cache, and then executes /usr/bin/su, resulting in the user obtaining a root shell. The on-disk binary is never modified. A reboot or cache flush restores normal system behavior.

⚙️ Fragnesia affects the same kernel versions as Dirty Frag. Any distribution shipping a kernel without the May 13 patch is vulnerable. The vulnerability was confirmed on Ubuntu 6.8.0-111-generic (April 11, 2026 build). Monitor kernel package updates for your Linux distribution(s).

For systems where a kernel update is not possible, the same workaround as for Dirty Frag is effective (blacklisting modules). Systems where the Dirty Frag workaround has already been applied are already protected against Fragnesia. Systems that only received Dirty Frag updates without applying the workaround remain vulnerable and require new updates addressing Fragnesia.

Trending vulnerabilities for June according to Positive Technologies

Trending vulnerabilities for June according to Positive Technologies. Traditionally, in 3 formats (in Russian):

📹 The section "Trending VM" in the SecLab news video (starts at 15:03)
🗞 Post on the Habr website, in fact this is a slightly expanded scenario for the "Trending VM" section
🗒 Compact digest with technical details on the official PT website

List of vulnerabilities:

🔻 EoP in Microsoft Windows CSC (CVE-2024-26229)
🔻 EoP in Microsoft Windows Error Reporting (CVE-2024-26169)
🔻 EoP in Microsoft Windows Kernel (CVE-2024-30088)
🔻 RCE in PHP (CVE-2024-4577)
🔻 EoP in Linux Kernel (CVE-2024-1086)
🔻 InfDisclosure in Check Point Security Gateways (CVE-2024-24919)
🔻 RCE in VMware vCenter (CVE-2024-37079, CVE-2024-37080)
🔻 AuthBypass in Veeam Backup & Replication (CVE-2024-29849)

На русском

Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086) has been added to CISA KEV

Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086) has been added to CISA KEV

Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086) has been added to CISA KEV. The vulnerability itself is relatively old, from January. I already wrote about it in March, when the write-up and public exploit were released.

Despite the fact that the exploitation of this vulnerability is trivial (the attacker launches a local utility and gains root privileges), until recently there were no signs of exploitation in the wild. This is quite strange: such a useful exploit should immediately be included in the attackers’ toolkit. So either the practical exploitation of this vulnerability is somehow complicated, or the attackers did not leave any traces. 🤔

In any case, on May 30, the vulnerability was added to CISA KEV, and this means the fact of its exploitation in attacks has been proven. But there are no details yet. Please be aware of this vulnerability when upgrading Linux hosts.

На русском

For the January Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086), the write-up and PoC were released on March 26

For the January Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086), the write-up and PoC were released on March 26
For the January Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086), the write-up and PoC were released on March 26

For the January Elevation of Privilege (Local Privilege Escalation) - Linux Kernel (CVE-2024-1086), the write-up and PoC were released on March 26. The video demo for the script looks impressive: they run the script as a regular user and after a couple of seconds they get a root shell. According to the author, the exploit works with most Linux kernels between versions 5.14 and 6.6, including Debian, Ubuntu and KernelCTF.

🔻 The exploit requires kconfig CONFIG_USER_NS=y; sh command sysctl kernel.unprivileged_userns_clone = 1; kconfig CONFIG_NF_TABLES=y. The author writes that this is the default for Debian, Ubuntu, and KernelCTF, and for other distributions it is necessary to test it.
🔹 The exploit does not work with kernels v6.4> with kconfig CONFIG_INIT_ON_ALLOC_DEFAULT_ON=y (including Ubuntu v6.5)

NSFOCUS writes that Redhat is also vulnerable. 🤷‍♂️

На русском