Headline
CVE-2023-32257: ZDI-23-705
A flaw was found in the Linux kernel’s ksmbd, a high-performance in-kernel SMB server. The specific flaw exists within the processing of SMB2_SESSION_SETUP and SMB2_LOGOFF commands. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to execute code in the context of the kernel.
May 17th, 2023
Linux Kernel ksmbd Session Race Condition Remote Code Execution Vulnerability****ZDI-23-705
ZDI-CAN-20596
CVE ID
CVE-2023-32257
CVSS SCORE
8.1, (AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H)
AFFECTED VENDORS
Linux
AFFECTED PRODUCTS
Kernel
VULNERABILITY DETAILS
This vulnerability allows remote attackers to execute arbitrary code on affected installations of Linux Kernel. Authentication is not required to exploit this vulnerability, but only systems with ksmbd enabled are vulnerable.
The specific flaw exists within the processing of SMB2_SESSION_SETUP and SMB2_LOGOFF commands. The issue results from the lack of proper locking when performing operations on an object. An attacker can leverage this vulnerability to execute code in the context of the kernel.
ADDITIONAL DETAILS
Linux has issued an update to correct this vulnerability. More details can be found at:
https://github.com/torvalds/linux/commit/f5c779b7ddbda30866cf2a27c63e34158f858c73
DISCLOSURE TIMELINE
- 2023-04-27 - Vulnerability reported to vendor
- 2023-05-17 - Coordinated public release of advisory
CREDIT
Quentin Minster (@thalium_team)
BACK TO ADVISORIES
Related news
Ubuntu Security Notice 6626-3 - Quentin Minster discovered that a race condition existed in the KSMBD implementation in the Linux kernel when handling sessions operations. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code. Marek Marczykowski-Górecki discovered that the Xen event channel infrastructure implementation in the Linux kernel contained a race condition. An attacker in a guest VM could possibly use this to cause a denial of service.
Ubuntu Security Notice 6628-2 - Quentin Minster discovered that a race condition existed in the KSMBD implementation in the Linux kernel when handling sessions operations. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code. Marek Marczykowski-Górecki discovered that the Xen event channel infrastructure implementation in the Linux kernel contained a race condition. An attacker in a guest VM could possibly use this to cause a denial of service.
Ubuntu Security Notice 6626-2 - Quentin Minster discovered that a race condition existed in the KSMBD implementation in the Linux kernel when handling sessions operations. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code. Marek Marczykowski-Górecki discovered that the Xen event channel infrastructure implementation in the Linux kernel contained a race condition. An attacker in a guest VM could possibly use this to cause a denial of service.
Ubuntu Security Notice 6628-1 - Quentin Minster discovered that a race condition existed in the KSMBD implementation in the Linux kernel when handling sessions operations. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code. Marek Marczykowski-Górecki discovered that the Xen event channel infrastructure implementation in the Linux kernel contained a race condition. An attacker in a guest VM could possibly use this to cause a denial of service.
Ubuntu Security Notice 6626-1 - Quentin Minster discovered that a race condition existed in the KSMBD implementation in the Linux kernel when handling sessions operations. A remote attacker could use this to cause a denial of service or possibly execute arbitrary code. Marek Marczykowski-Górecki discovered that the Xen event channel infrastructure implementation in the Linux kernel contained a race condition. An attacker in a guest VM could possibly use this to cause a denial of service.
Ubuntu Security Notice 6338-2 - Zi Fan Tan discovered that the binder IPC implementation in the Linux kernel contained a use-after-free vulnerability. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. It was discovered that a race condition existed in the f2fs file system in the Linux kernel, leading to a null pointer dereference vulnerability. An attacker could use this to construct a malicious f2fs image that, when mounted and operated on, could cause a denial of service.
Ubuntu Security Notice 6344-1 - Zi Fan Tan discovered that the binder IPC implementation in the Linux kernel contained a use-after-free vulnerability. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. It was discovered that a race condition existed in the f2fs file system in the Linux kernel, leading to a null pointer dereference vulnerability. An attacker could use this to construct a malicious f2fs image that, when mounted and operated on, could cause a denial of service.
Ubuntu Security Notice 6338-1 - Zi Fan Tan discovered that the binder IPC implementation in the Linux kernel contained a use-after-free vulnerability. A local attacker could use this to cause a denial of service or possibly execute arbitrary code. It was discovered that a race condition existed in the f2fs file system in the Linux kernel, leading to a null pointer dereference vulnerability. An attacker could use this to construct a malicious f2fs image that, when mounted and operated on, could cause a denial of service.