Article Detail

Product Affected

This issue affects Junos OS 12.3, 15.1, 17.3, 18.4, 19.1, 19.2, 19.3, 19.4, 20.1, 20.2, 20.3, 20.4, 21.1, 21.2, 21.3, 21.4, 22.1, 22.2, 22.3.

Severity

High

Severity Assessment (CVSS) Score

7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Problem

An Uncontrolled Resource Consumption vulnerability in TCP processing on the Routing Engine (RE) of Juniper Networks Junos OS allows an unauthenticated network-based attacker to send crafted TCP packets destined to the device, resulting in an MBUF leak that ultimately leads to a Denial of Service (DoS). The system does not recover automatically and must be manually restarted to restore service.

This issue occurs when crafted TCP packets are sent directly to a configured IPv4 or IPv6 interface on the device. Transit traffic will not trigger this issue.

MBUF usage can be monitored through the use of the 'show system buffers' command. For example:

user@junos> show system buffers | refresh 5
4054/566/4620 mbufs in use (current/cache/total)
...
4089/531/4620 mbufs in use (current/cache/total)
...
4151/589/4740 mbufs in use (current/cache/total)
...
4213/527/4740 mbufs in use (current/cache/total)

This issue affects Juniper Networks Junos OS:

12.3 version 12.3R12-S19 and later versions;
15.1 version 15.1R7-S10 and later versions;
17.3 version 17.3R3-S12 and later versions;
18.4 version 18.4R3-S9 and later versions;
19.1 version 19.1R3-S7 and later versions;
19.2 version 19.2R3-S3 and later versions;
19.3 version 19.3R2-S7, 19.3R3-S3 and later versions prior to 19.3R3-S7;
19.4 version 19.4R2-S7, 19.4R3-S5 and later versions prior to 19.4R3-S10;
20.1 version 20.1R3-S1 and later versions;
20.2 version 20.2R3-S2 and later versions prior to 20.2R3-S6;
20.3 version 20.3R3-S1 and later versions prior to 20.3R3-S6;
20.4 version 20.4R2-S2, 20.4R3 and later versions prior to 20.4R3-S5;
21.1 version 21.1R2 and later versions prior to 21.1R3-S4;
21.2 version 21.2R1-S1, 21.2R2 and later versions prior to 21.2R3-S3;
21.3 versions prior to 21.3R3-S2;
21.4 versions prior to 21.4R3;
22.1 versions prior to 22.1R2-S1, 22.1R3;
22.2 versions prior to 22.2R1-S2, 22.2R2;
22.3 versions prior to 22.3R1-S1, 22.3R2.

Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2023-22396.

Solution

The following software releases have been updated to resolve this specific issue: Junos OS 19.3R3-S7, 19.4R3-S10, 20.2R3-S6, 20.3R3-S6, 20.4R3-S5, 21.1R3-S4, 21.2R3-S3, 21.3R3-S2, 21.4R3, 22.1R2-S1, 22.1R3, 22.2R1-S2, 22.2R2, 22.2R3, 22.3R1-S1, 22.3R2, 22.4R1, and all subsequent releases.

This issue is being tracked as 1670303.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

Workaround

To reduce the risk of malicious exploitation, limit the exploitable attack surface of critical infrastructure networking equipment. Use access lists or firewall filters to limit access to the device only from trusted, administrative networks or hosts.

Severity Assessment

Information for how Juniper Networks uses CVSS can be found at KB 16446 [juniper.net] "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

Modification History