CVE-2024-50102
AMD x86 Spectre
Description
In the Linux kernel, the following vulnerability has been resolved: x86: fix user address masking non-canonical speculation issue It turns out that AMD has a "Meltdown Lite(tm)" issue with non-canonical accesses in kernel space. And so using just the high bit to decide whether an access is in user space or kernel space ends up with the good old "leak speculative data" if you have the right gadget using the result: CVE-2020-12965 “Transient Execution of Non-Canonical Accesses“ Now, the kernel surrounds the access with a STAC/CLAC pair, and those instructions end up serializing execution on older Zen architectures, which closes the speculation window. But that was true only up until Zen 5, which renames the AC bit [1]. That improves performance of STAC/CLAC a lot, but also means that the speculation window is now open. Note that this affects not just the new address masking, but also the regular valid_user_address() check used by access_ok(), and the asm version of the sign bit check in the get_user() helpers. It does not affect put_user() or clear_user() variants, since there's no speculative result to be used in a gadget for those operations.
INFO
Published Date :
Nov. 5, 2024, 6:15 p.m.
Last Modified :
Nov. 12, 2024, 3:08 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2024-50102.
| URL | Resource |
|---|---|
| https://git.kernel.org/stable/c/291313693677a345d4f50aae3c68e28b469f601e | Patch |
| https://git.kernel.org/stable/c/86e6b1547b3d013bc392adf775b89318441403c2 | Patch |
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2024-50102 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-50102 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Reanalysis by [email protected]
Nov. 12, 2024
Action Type Old Value New Value Removed CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N -
Initial Analysis by [email protected]
Nov. 12, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://git.kernel.org/stable/c/291313693677a345d4f50aae3c68e28b469f601e No Types Assigned https://git.kernel.org/stable/c/291313693677a345d4f50aae3c68e28b469f601e Patch Changed Reference Type https://git.kernel.org/stable/c/86e6b1547b3d013bc392adf775b89318441403c2 No Types Assigned https://git.kernel.org/stable/c/86e6b1547b3d013bc392adf775b89318441403c2 Patch Added CWE NIST CWE-203 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.4 up to (excluding) 6.11.6 *cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.12:rc4:*:*:*:*:*:* -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Nov. 05, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: x86: fix user address masking non-canonical speculation issue It turns out that AMD has a "Meltdown Lite(tm)" issue with non-canonical accesses in kernel space. And so using just the high bit to decide whether an access is in user space or kernel space ends up with the good old "leak speculative data" if you have the right gadget using the result: CVE-2020-12965 “Transient Execution of Non-Canonical Accesses“ Now, the kernel surrounds the access with a STAC/CLAC pair, and those instructions end up serializing execution on older Zen architectures, which closes the speculation window. But that was true only up until Zen 5, which renames the AC bit [1]. That improves performance of STAC/CLAC a lot, but also means that the speculation window is now open. Note that this affects not just the new address masking, but also the regular valid_user_address() check used by access_ok(), and the asm version of the sign bit check in the get_user() helpers. It does not affect put_user() or clear_user() variants, since there's no speculative result to be used in a gadget for those operations. Added Reference kernel.org https://git.kernel.org/stable/c/291313693677a345d4f50aae3c68e28b469f601e [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/86e6b1547b3d013bc392adf775b89318441403c2 [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-50102 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-50102
weaknesses.