A Missing Release of Resource after Effective Lifetime vulnerability the xinetd process, responsible for spawning SSH daemon (sshd) instanc…
A Missing Release of Resource after Effective Lifetime vulnerability the xinetd process, responsible for spawning SSH daemon (sshd) instances, of Juniper Networks Junos OS Evolved allows an unauthenticated network-based attacker to cause a Denial of Service (DoS) by blocking SSH access for legitimate users. Continued receipt of these connections will create a sustained Denial of Service (DoS) condition. The issue is triggered when a high rate of concurrent SSH requests are received and terminated in a specific way, causing xinetd to crash, and leaving defunct sshd processes. Successful exploitation of this vulnerability blocks both SSH access as well as services which rely upon SSH, such as SFTP, and Netconf over SSH. Once the system is in this state, legitimate users will be unable to SSH to the device until service is manually restored. See WORKAROUND section below. Administrators can monitor an increase in defunct sshd processes by utilizing the CLI command: > show system processes | match sshd root 25219 30901 0 Jul16 ? 00:00:00 [sshd] <defunct> This issue affects Juniper Networks Junos OS Evolved: * All versions prior to 21.4R3-S7-EVO * 22.3-EVO versions prior to 22.3R2-S2-EVO, 22.3R3-S2-EVO; * 22.4-EVO versions prior to 22.4R3-EVO; * 23.2-EVO versions prior to 23.2R2-EVO. This issue does not affect Juniper Networks Junos OS Evolved 22.1-EVO nor 22.2-EVO.
The product does not release a resource after its effective lifetime has ended, i.e., after the resource is no longer needed.
https://cwe.mitre.org/data/definitions/772.html →Open in CWE collection →An attacker performs flooding at the HTTP level to bring down only a particular web application rather than anything listening on a TCP/IP connection. This denial of service attack requires substantially fewer packets to be sent which makes DoS harder to detect. This is an equivalent of SYN flood in HTTP. The idea is to keep the HTTP session alive indefinitely and then repeat that hundreds of times. This attack targets resource depletion weaknesses in web server software. The web server will wait to attacker's responses on the initiated HTTP sessions while the connection threads are being exhausted.
https://capec.mitre.org/data/definitions/469.html →Open in CAPEC collection →| Product | Vendor | Status |
|---|---|---|
| junos_os_evolved | * | Tracked |