ClevOS update for IBM Cloud Object Storage Systems

1) Out-of-bounds read

EUVDB-ID: #VU67490

Risk: Low

CVSSv3.1: 4 [CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2021-29155

CWE-ID: CWE-125 - Out-of-bounds read

Exploit availability: Yes

Description

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists in retrieve_ptr_limit in kernel/bpf/verifier.c in the Linux kernel mechanism. A local, special user privileged (CAP_SYS_ADMIN) BPF program running on affected systems may bypass the protection, and execute speculatively out-of-bounds loads from the kernel memory.

Mitigation

Install update from vendor's website.

Vulnerable software versions

ClevOS: All versions

External links

http://www.ibm.com/blogs/psirt/security-bulletin-multiple-vulnerabilities-affect-ibm-cloud-object-storage-systems-oct-2021-v2/

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Race condition

EUVDB-ID: #VU53006

Risk: Low

CVSSv3.1: 7.7 [CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2021-23133

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Exploit availability: No

Description

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition in Linux kernel SCTP sockets (net/sctp/socket.c). If sctp_destroy_sock is called without sock_net(sk)->sctp.addr_wq_lock then an element is removed from the auto_asconf_splist list without any proper locking. This can be exploited by a local user with network service privileges to escalate to root or from the context of an unprivileged user directly if a BPF_CGROUP_INET_SOCK_CREATE is attached which denies creation of some SCTP socket.

Mitigation

Install update from vendor's website.

Vulnerable software versions

ClevOS: All versions

External links

http://www.ibm.com/blogs/psirt/security-bulletin-multiple-vulnerabilities-affect-ibm-cloud-object-storage-systems-oct-2021-v2/

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.