CVE-2026-31517

Description

A flaw was found in the Linux kernel's IP-TFS (IP-Transparent Fragmentation Service) subsystem. A remote attacker could send specially crafted network packets that, during the reassembly process, cause the kernel to attempt an invalid operation on a network buffer. This improper handling of network packet fragments can lead to a system crash, resulting in a Denial of Service (DoS).

Understanding the Weakness (CWE)

Confidentiality

Technical Impact: Read Memory

For an out-of-bounds read, the attacker may have access to sensitive information. If the sensitive information contains system details, such as the current buffer's position in memory, this knowledge can be used to craft further attacks, possibly with more severe consequences.

Integrity,Availability

Technical Impact: Modify Memory; DoS: Crash, Exit, or Restart

Out of bounds memory access will very likely result in the corruption of relevant memory, and perhaps instructions, possibly leading to a crash. Other attacks leading to lack of availability are possible, including putting the program into an infinite loop.

Integrity

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

If the memory accessible by the attacker can be effectively controlled, it may be possible to execute arbitrary code, as with a standard buffer overflow. If the attacker can overwrite a pointer's worth of memory (usually 32 or 64 bits), they can redirect a function pointer to their own malicious code. Even when the attacker can only modify a single byte arbitrary code execution can be possible. Sometimes this is because the same problem can be exploited repeatedly to the same effect. Other times it is because the attacker can overwrite security-critical application-specific data -- such as a flag indicating whether the user is an administrator.

Frequently Asked Questions

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