Vulnerability Details : CVE-2017-5551
The simple_set_acl function in fs/posix_acl.c in the Linux kernel before 4.9.6 preserves the setgid bit during a setxattr call involving a tmpfs filesystem, which allows local users to gain group privileges by leveraging the existence of a setgid program with restrictions on execute permissions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2016-7097.
Products affected by CVE-2017-5551
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2017-5551
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 6 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2017-5551
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
3.6
|
LOW | AV:L/AC:L/Au:N/C:P/I:P/A:N |
3.9
|
4.9
|
NIST | |
|
4.4
|
MEDIUM | CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N |
1.8
|
2.5
|
NIST |
References for CVE-2017-5551
-
http://www.debian.org/security/2017/dsa-3791
Debian -- Security Information -- DSA-3791-1 linux
-
https://github.com/torvalds/linux/commit/497de07d89c1410d76a15bec2bb41f24a2a89f31
tmpfs: clear S_ISGID when setting posix ACLs · torvalds/linux@497de07 · GitHubIssue Tracking;Patch;Third Party Advisory
-
https://bugzilla.redhat.com/show_bug.cgi?id=1416126
1416126 – (CVE-2017-5551) CVE-2017-5551 kernel: S_ISGD is not cleared when setting posix ACLs in tmpfs (CVE-2016-7097 incomplete fix)Issue Tracking;Patch
-
http://www.securityfocus.com/bid/95717
Linux Kernel CVE-2017-5551 Local Denial of Service VulnerabilityThird Party Advisory;VDB Entry
-
http://www.securitytracker.com/id/1038053
Linux Kernel 'tmpfs' File System Permission Flaw Lets Local Users Gain Elevated Privileges - SecurityTracker
-
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=497de07d89c1410d76a15bec2bb41f24a2a89f31
kernel/git/torvalds/linux.git - Linux kernel source treeIssue Tracking;Patch;Third Party Advisory
-
http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.6
Release Notes;Vendor Advisory
-
http://www.openwall.com/lists/oss-security/2017/01/21/3
oss-security - Re: CVE REQUEST: linux kernel: process with pgid zero able to crash kernelMailing List;Patch;Third Party Advisory
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