CVE-2024-21980
Description
A flaw was found in SNP firmware. This vulnerability allows a malicious hypervisor to overwrite a guest's memory or UMC seed, resulting in loss of confidentiality and integrity via improper restriction of write operations.
Statement
Red Hat has very limited to no visibility and control over binary blobs provided by third-party vendors. Red Hat relies heavily on the vendors to provide timely updates and information about included changes for this content and in most cases merely acts as a release vehicle between the third-party vendor and Red Hat customers with no possibility of influencing or even documenting the changes. Unless explicitly stated, the level of insight, oversight, and control Red Hat has does not meet the criteria required (in terms of Red Hat ownership of development processes, QA, and documentation) for releasing this content as RHSA. For more information please contact the binary content vendor.
Mitigation
Available mitigation requires to update BIOS (for updating firmware of CPU). The bug affects hardware (processors of AMD EPYC™ family).
Understanding the Weakness (CWE)
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands; Modify Memory
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 alter the intended control flow by redirecting 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.
Availability,Confidentiality
Technical Impact: Read Memory; DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
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.
Confidentiality
Technical Impact: Read Memory
In the case of 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.
Frequently Asked Questions
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