Security Bulletin: Multiple Vulnerabilities in the Linux kernel affect the IBM FlashSystem 840 and 900

Summary

There are vulnerabilities in the Linux kernel to which the IBM FlashSystem™ 840 and FlashSystem 900 are susceptible (CVE-2017-18017 and CVE-2017-17449). An exploit of CVE-2017-18017 could allow a remote attacker to cause a denial of service condition. An exploit of CVE-2017-17449 could allow an attacker to obtain sensitive information.

Vulnerability Details

CVEID: CVE-2017-18017 DESCRIPTION: Linux Kernel is vulnerable to a denial of service, caused by a use-after-free flaw in the tcpmss_mangle_packet function in net/netfilter/xt_TCPMSS.c. By leveraging the presence of xt_TCPMSS in an iptables action, a remote attacker could exploit this vulnerability to cause a denial of service condition.
CVSS Base Score: 7.5
CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/137122&gt; for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

CVEID: CVE-2017-17449 DESCRIPTION: Linux Kernel could allow a local attacker to obtain sensitive information, caused by the failure to restrict observations of Netlink messages to a single net namespace when CONFIG_NLMON is enabled in the __netlink_deliver_tap_skb function in net/netlink/af_netlink.c. By leveraging the CAP_NET_ADMIN capability to sniff an nlmon interface for all Netlink activity on the system, an attacker could exploit this vulnerability to obtain sensitive information.
CVSS Base Score: 6.2
CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/136106&gt; for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)

Affected Products and Versions

FlashSystem 840 machine type and models (MTMs) affected include 9840-AE1 and 9843-AE1.
FlashSystem 900 MTMs affected include 9843-UF3, 9840-AE2, 9843-AE2, 9840-AE3, and 9843-AE3.

Supported code versions which are affected

• VRMFs prior to 1.4.8.2
• VRMFs prior to 1.5.2.5
• VRMFs prior to 1.6.1.0

Remediation/Fixes

MTMs

| VRMF | APAR | Remediation/First Fix
—|—|—|—
FlashSystem****840 MTM:
9840-AE1 &9843-AE1

**FlashSystem 900 MTMs:**9843-UF3, 9840-AE2, 9843-AE2, 9840-AE3, & 9843-AE3 |

Code fixes are now available, the minimum VRMF containing the fix depends on the code stream:_ _
__Fixed Code VRMF __
1.6 stream: 1.6.1.0

1.5 stream: 1.5.2.5

1.4 stream: 1.4.8.2

| N/A | FlashSystem 840 fixesand FlashSystem 900 fixes****are available @ IBM’s Fix Central

Workarounds and Mitigations

Upgrade to a remediated code level.