SUSE update for nginx

1) Off-by-one

EUVDB-ID: #VU53543

Risk: High

CVSSv4.0: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P/U:Amber]

CVE-ID: CVE-2021-23017

CWE-ID: CWE-193 - Off-by-one Error

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to an off-by-one error within the ngx_resolver_copy() function when processing DNS responses. A remote attacker can trigger an off-by-one error, write a dot character (‘.’, 0x2E) out of bounds in a heap allocated buffer and execute arbitrary code on the system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

The vulnerability can be triggered by a DNS response in reply to a DNS request from nginx when the resolver primitive is configured. A specially crafted packet allows overwriting the least significant byte of next heap chunk metadata with 0x2E.

Mitigation

Update the affected package nginx to the latest version.

Vulnerable software versions

SUSE Manager Proxy: 4.0

SUSE Manager Retail Branch Server: 4.0

SUSE Manager Server: 4.0

SUSE Linux Enterprise Server for SAP: 15-SP1

SUSE Linux Enterprise High Performance Computing: 15-SP1-LTSS - 15-SP1-ESPOS

SUSE Enterprise Storage: 6

SUSE CaaS Platform: 4.0

SUSE Linux Enterprise Server: 15-SP1-BCL - 15-SP1-LTSS

nginx-source: before 1.16.1-6.13.1

nginx-debugsource: before 1.16.1-6.13.1

nginx-debuginfo: before 1.16.1-6.13.1

nginx: before 1.16.1-6.13.1

CPE2.3

• cpe:2.3:o:suse:suse_manager_proxy:4.0:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_manager_retail_branch_server:4.0:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_manager_server:4.0:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_server_for_sap:15-SP1:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_high_performance_computing:15-SP1-LTSS:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_high_performance_computing:15-SP1-ESPOS:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_enterprise_storage:6:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_caas_platform:4.0:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_server:15-SP1-BCL:*:*:*:*:*:*:*
• cpe:2.3:o:suse:suse_linux_enterprise_server:15-SP1-LTSS:*:*:*:*:*:*:*
• cpe:2.3:a:suse:nginx-source:*:*:*:*:*:suse_linux:*:*
• cpe:2.3:a:suse:nginx-debugsource:*:*:*:*:*:suse_linux:*:*
• cpe:2.3:a:suse:nginx-debuginfo:*:*:*:*:*:suse_linux:*:*
• cpe:2.3:a:suse:nginx:*:*:*:*:*:suse_linux:*:*

External links

https://www.suse.com/support/update/announcement/2021/suse-su-20211839-1/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

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.