CVE-2024-56614 CVE-2024-56615: PoC Exploits Released for Severe eBPF Vulnerabilities in Linux Kernel

While these Linux kernel eBPF vulnerabilities enable initial memory corruption through integer overflow errors, BlueRock's defense-in-depth approach significantly reduces their impact. These vulnerabilities may allow attackers to achieve initial memory corruption, but BlueRock's security mechanisms contain and mitigate the attack's progression in several key ways. Kernel Integrity Protection and Integrity Patch Violation prevent unauthorized modifications to kernel code segments, blocking attempts to inject malicious code following successful memory corruption. Process Credential Protection and DirtyCred Protection safeguard critical credential structures, preventing the privilege escalation paths that attackers typically pursue after exploiting kernel memory vulnerabilities. Privileged Inode Protection blocks attempts to modify sensitive filesystem objects and kernel interfaces that attackers frequently target to establish persistence. Register Protect helps maintain the integrity of CPU registers during exploitation attempts, potentially disrupting control flow hijacking techniques. Page Table Protection prevents attacks from escalating to compromise memory isolation mechanisms if attackers attempt to target page tables during later exploitation stages. This multi-layered approach ensures that even if an attacker successfully exploits the initial memory corruption vulnerability, BlueRock significantly restricts their ability to achieve meaningful objectives such as privilege escalation, persistent access, or data exfiltration.

• T1068: Exploitation for Privilege Escalation: The article discusses two vulnerabilities, CVE-2024-56614 and CVE-2024-56615, in the Linux kernel's eBPF framework. Both vulnerabilities allow attackers to exploit integer overflow errors in critical functions, leading to out-of-bounds writes and memory corruption. This aligns with the MITRE ATT&CK technique for exploiting public-facing applications, as the vulnerabilities can be leveraged to gain control over the kernel. This is an example of Exploitation for Privilege Escalation, where the attacker uses a vulnerability to execute arbitrary code with elevated privileges.
• T1203: Exploitation for Client Execution: The vulnerabilities allow an attacker to perform an out-of-bounds write operation, which can lead to memory corruption and potential control flow hijacking. This action corresponds to the MITRE ATT&CK technique for hijacking execution flow through exploitation, as the attacker can manipulate the program execution flow to execute arbitrary code.
• T1068: Exploitation for Privilege Escalation: The successful exploitation of these vulnerabilities could lead to a complete system compromise, allowing the attacker to gain root privileges and execute arbitrary code. This scenario aligns with the MITRE ATT&CK technique for Privilege Escalation, where an attacker gains higher-level permissions on a system.

F1: Exploitation of CVE-2024-56614 via integer overflow in xskmapdelete_elem within the AF_XDP framework, leading to kernel memory corruption.

• Attacker targets the xskmapdelete_elem function within the Linux kernel's eBPF framework, specifically related to AFXDP sockets used for high-performance packet processing. (Cited from: "CVE-2024-56614: This vulnerability resides within the xskmapdeleteelem function, which is part of the AFXDP sockets framework.", "AFXDP is designed for high-performance packet processing")
• Attacker crafts input that triggers an implicit type conversion between an unsigned integer and a signed integer during a bounds check within the function. (Cited from: "Both vulnerabilities stem from the same root cause: an implicit type conversion between an unsigned integer and a signed integer during a bounds check.")
• The crafted input includes a value that, after the type conversion, becomes a negative value, allowing it to bypass the intended bounds check. (Cited from: "This allows for a negative value to bypass the check")
• The bypassed check leads to an integer overflow, resulting in an out-of-bounds write operation within kernel memory. (Cited from: "resulting in an out-of-bounds write operation.", "exploit integer overflow errors in critical functions, leading to out-of-bounds writes")
  • BR-35: Kernel Integrity Protection - This mechanism is applicable because it protects kernel code and data regions by logging or blocking unauthorized write attempts. An out-of-bounds write resulting from the integer overflow is an unauthorized write into kernel memory, which this mechanism aims to prevent or detect.
  • BR-45: Page Table Protection - This mechanism is applicable if the out-of-bounds write targets the static portions of the kernel's page tables. It verifies the integrity of these tables, and an unauthorized write could corrupt them, triggering detection or prevention.
  • BR-39: Integrity Patch Violation - This mechanism is applicable conceptually as it detects unauthorized modifications (patches) to the kernel. While an OOB write isn't a typical patch, it represents an unauthorized modification of kernel memory, aligning with the goal of preventing integrity violations.
• This out-of-bounds write causes memory corruption within the Linux kernel. (Cited from: "memory corruption")
  • BR-35: Kernel Integrity Protection - This mechanism is applicable as it is designed to protect kernel code and read-only data regions from unauthorized writes. The memory corruption resulting from the OOB write constitutes such an unauthorized modification, which this mechanism aims to prevent or detect.
  • BR-45: Page Table Protection - This mechanism is applicable if the memory corruption affects the static portions of the kernel's page tables. It monitors these specific regions for unauthorized changes.
  • BR-39: Integrity Patch Violation - This mechanism is applicable because it detects unauthorized modifications to the kernel. The memory corruption caused by the exploit represents such an unauthorized change, potentially triggering this protection.
• The attacker leverages the memory corruption to potentially gain control of the kernel, achieve arbitrary code execution, gain root privileges, or cause a complete system compromise. (Cited from: "potentially gain control of the kernel, leading to arbitrary code execution.", "A successful attack could lead to a complete system compromise, allowing the attacker to gain root privileges and execute arbitrary code.")
  • BR-73: Kernel CET/IBT Guard - This mechanism is applicable because it uses Intel CET/IBT to prevent control-flow hijacking techniques like Jump-Oriented Programming (JOP) and potentially Return-Oriented Programming (ROP) if Shadow Stack (BR-81) is also considered. Arbitrary code execution often relies on hijacking the kernel's control flow, which CET/IBT aims to block.
  • BR-30: Process Credential Protection - This mechanism is applicable as it monitors and protects process credential structures from unauthorized modification. Gaining root privileges often involves tampering with these structures (e.g., setting UID/GID to 0), which this mechanism aims to detect and prevent.
  • BR-46: DirtyCred Protection - This mechanism is conceptually applicable as it prevents privilege escalation by detecting attempts to swap kernel credentials, even though the initial vulnerability is not file-based. If the memory corruption is used to manipulate credential structures similarly to DirtyCred, this protection could detect or block the privilege escalation attempt.
  • BR-31: Privileged Inode Protection - This mechanism is applicable if the arbitrary code execution attempts to modify security-relevant fields of privileged inodes (e.g., SUID/SGID files) to establish persistence or further escalate privileges. It tracks the integrity of these fields.
  • BR-28: Register Protect - This mechanism is applicable if the arbitrary code execution attempts involve modifying critical system registers to gain control or escalate privileges. It allows auditing or blocking of unauthorized register writes.
• The attack is facilitated by the availability of Proof-of-concept exploit code. (Cited from: "Proof-of-concept exploit code has been released for both vulnerabilities, significantly increasing the likelihood of active exploitation.")

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F2: Exploitation of CVE-2024-56615 via integer overflow in devmapmapdelete_elem within the DEVMAP component of eBPF, leading to kernel memory corruption.

• Attacker targets the devmapmapdelete_elem function within the Linux kernel's eBPF framework, specifically related to the DEVMAP component. (Cited from: "CVE-2024-56615: Similar to CVE-2024-56614, this vulnerability involves an integer overflow condition, but within the devmapmapdelete_elem function.", "This function is associated with DEVMAP, another component within the eBPF ecosystem.")
• Attacker crafts input that triggers an implicit type conversion between an unsigned integer and a signed integer during a bounds check within the function. (Cited from: "Both vulnerabilities stem from the same root cause: an implicit type conversion between an unsigned integer and a signed integer during a bounds check.")
• The crafted input includes a value that, after the type conversion, becomes a negative value, allowing it to bypass the intended bounds check. (Cited from: "This allows for a negative value to bypass the check")
• The bypassed check leads to an integer overflow, resulting in an out-of-bounds write operation within kernel memory. (Cited from: "resulting in an out-of-bounds write operation.", "exploit integer overflow errors in critical functions, leading to out-of-bounds writes")
  • BR-35: Kernel Integrity Protection - This mechanism is applicable because it protects kernel code and data regions from unauthorized writes. The OOB write resulting from the integer overflow is an unauthorized write into kernel memory, which this mechanism aims to prevent or detect.
  • BR-45: Page Table Protection - This mechanism is applicable if the out-of-bounds write targets the static portions of the kernel's page tables. It verifies the integrity of these tables, and an unauthorized write could corrupt them, triggering detection or prevention.
  • BR-39: Integrity Patch Violation - This mechanism is applicable conceptually as it detects unauthorized modifications (patches) to the kernel. While an OOB write isn't a typical patch, it represents an unauthorized modification of kernel memory, aligning with the goal of preventing integrity violations.
• This out-of-bounds write causes memory corruption within the Linux kernel. (Cited from: "memory corruption")
  • BR-35: Kernel Integrity Protection - This mechanism is applicable as it is designed to protect kernel code and read-only data regions from unauthorized writes. The memory corruption resulting from the OOB write constitutes such an unauthorized modification, which this mechanism aims to prevent or detect.
  • BR-45: Page Table Protection - This mechanism is applicable if the memory corruption affects the static portions of the kernel's page tables. It monitors these specific regions for unauthorized changes.
  • BR-39: Integrity Patch Violation - This mechanism is applicable because it detects unauthorized modifications to the kernel. The memory corruption caused by the exploit represents such an unauthorized change, potentially triggering this protection.
• The attacker leverages the memory corruption to potentially compromise the kernel, execute malicious code, gain root privileges, or cause a complete system compromise. (Cited from: "Successful exploitation could allow an attacker to compromise the kernel and execute malicious code.", "A successful attack could lead to a complete system compromise, allowing the attacker to gain root privileges and execute arbitrary code.")
  • BR-73: Kernel CET/IBT Guard - This mechanism is applicable because it uses Intel CET/IBT to prevent control-flow hijacking techniques like Jump-Oriented Programming (JOP). Executing malicious code often involves hijacking the kernel's control flow, which CET/IBT aims to block.
  • BR-30: Process Credential Protection - This mechanism is applicable as it monitors and protects process credential structures from unauthorized modification. Gaining root privileges often involves tampering with these structures (e.g., setting UID/GID to 0), which this mechanism aims to detect and prevent.
  • BR-46: DirtyCred Protection - This mechanism is conceptually applicable as it prevents privilege escalation by detecting attempts to swap kernel credentials. If the memory corruption is used to manipulate credential structures in a way similar to DirtyCred, this protection could detect or block the privilege escalation attempt.
  • BR-31: Privileged Inode Protection - This mechanism is applicable if the malicious code execution attempts to modify security-relevant fields of privileged inodes (e.g., SUID/SGID files) to establish persistence or further escalate privileges. It tracks the integrity of these fields.
  • BR-28: Register Protect - This mechanism is applicable if the malicious code execution attempts involve modifying critical system registers to gain control or escalate privileges. It allows auditing or blocking of unauthorized register writes.
• The attack is facilitated by the availability of Proof-of-concept exploit code. (Cited from: "Proof-of-concept exploit code has been released for both vulnerabilities, significantly increasing the likelihood of active exploitation.")