CVE-2017-1000255 — MEDIUM (5.5)

Vulnerability Description

On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from the signal frame* as the kernel stack pointer. As part of the exception entry the content of the signal frame is written to the kernel stack, allowing an attacker to overwrite arbitrary locations with arbitrary values. The exception handling does produce an oops, and a panic if panic_on_oops=1, but only after kernel memory has been over written. This flaw was introduced in commit: "5d176f751ee3 (powerpc: tm: Enable transactional memory (TM) lazily for userspace)" which was merged upstream into v4.9-rc1. Please note that kernels built with CONFIG_PPC_TRANSACTIONAL_MEM=n are not vulnerable.

CVSS Score

5.5

MEDIUM

CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

NONE

Integrity

HIGH

Availability

NONE

Affected Products

Vendor	Product	Versions
Linux	Linux Kernel	-
Ibm	Powerpc Power8	-
Ibm	Powerpc Power9	-

Related Weaknesses (CWE)

CWE-787

References

http://www.securityfocus.com/bid/101264Third Party AdvisoryVDB Entry
https://access.redhat.com/errata/RHSA-2018:0654
https://access.redhat.com/security/cve/CVE-2017-1000255Issue TrackingThird Party Advisory
http://www.securityfocus.com/bid/101264Third Party AdvisoryVDB Entry
https://access.redhat.com/errata/RHSA-2018:0654
https://access.redhat.com/security/cve/CVE-2017-1000255Issue TrackingThird Party Advisory

FAQ

What is CVE-2017-1000255?

CVE-2017-1000255 is a vulnerability with a CVSS score of 5.5 (MEDIUM). On Linux running on PowerPC hardware (Power8 or later) a user process can craft a signal frame and then do a sigreturn so that the kernel will take an exception (interrupt), and use the r1 value *from...

How severe is CVE-2017-1000255?

CVE-2017-1000255 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2017-1000255?

Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Ibm Powerpc Power8, Ibm Powerpc Power9.