CVE-2021-34781— Cisco Firepower Threat Defense Software SSH Connections Denial of Service Vulnerability
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I. Basic Information for CVE-2021-34781
Vulnerability Information
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Vulnerability Title
Cisco Firepower Threat Defense Software SSH Connections Denial of Service Vulnerability
Source: NVD (National Vulnerability Database)
Vulnerability Description
A vulnerability in the processing of SSH connections for multi-instance deployments of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. This vulnerability is due to a lack of proper error handling when an SSH session fails to be established. An attacker could exploit this vulnerability by sending a high rate of crafted SSH connections to the instance. A successful exploit could allow the attacker to cause resource exhaustion, which causes a DoS condition on the affected device. The device must be manually reloaded to recover.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Source: NVD (National Vulnerability Database)
Vulnerability Type
内存缓冲区边界内操作的限制不恰当
Source: NVD (National Vulnerability Database)
Vulnerability Title
Cisco Firepower Threat Defense 缓冲区错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Cisco Firepower Threat Defense（FTD）是美国思科（Cisco）公司的一套提供下一代防火墙服务的统一软件。 Cisco Firepower Threat Defense Software 存在缓冲区错误漏洞，该漏洞源于在无法建立 SSH 会话时缺乏正确的错误处理。攻击者可以通过向实例发送高频率的精心设计的 SSH 连接来利用此漏洞。成功的利用可能允许攻击者造成资源耗尽，从而导致受影响设备出现 DoS 条件。必须手动重新加载设备才能恢复。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)
Affected Products
| Vendor | Product | Affected Versions | CPE | Subscribe |
|---|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | n/a | - |
II. Public POCs for CVE-2021-34781
| # | POC Description | Source Link | Shenlong Link |
|---|
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- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-dos-rUDseW3rvendor-advisoryx_refsource_CISCO
- https://nvd.nist.gov/vuln/detail/CVE-2021-34781
Same Patch Batch · Cisco · 2021-10-27 · 20 CVEs total
| CVE-2021-40117 | 8.6 HIGH | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SSL/TLS D |
| CVE-2021-40116 | 8.6 HIGH | Multiple Cisco Products Snort Rule Denial of Service Vulnerability |
| CVE-2021-40118 | 8.6 HIGH | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Servi |
| CVE-2021-34793 | 8.6 HIGH | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Transpare |
| CVE-2021-34792 | 8.6 HIGH | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Resource |
| CVE-2021-34783 | 8.6 HIGH | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Software- |
| CVE-2021-34762 | 8.1 HIGH | Cisco Firepower Management Center Software Authenticated Directory Traversal Vulnerability |
| CVE-2021-40114 | 6.8 MEDIUM | Multiple Cisco Products Snort Memory Leak Denial of Service Vulnerability |
| CVE-2021-34755 | 6.7 MEDIUM | Cisco Firepower Threat Defense Software Command Injection Vulnerabilities |
| CVE-2021-34756 | 6.7 MEDIUM | Cisco Firepower Threat Defense Software Command Injection Vulnerabilities |
| CVE-2021-34754 | 5.8 MEDIUM | Cisco Firepower Threat Defense Software Ethernet Industrial Protocol Policy Bypass Vulnera |
| CVE-2021-40125 | 5.3 MEDIUM | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software IKEv2 Sit |
| CVE-2021-34787 | 5.3 MEDIUM | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Identity- |
| CVE-2021-34794 | 5.3 MEDIUM | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software SNMP Acce |
| CVE-2021-34763 | 4.8 MEDIUM | Cisco Firepower Management Center Software Cross-Site Scripting and Open Redirect Vulnerab |
| CVE-2021-34764 | 4.8 MEDIUM | Cisco Firepower Management Center Software Cross-Site Scripting and Open Redirect Vulnerab |
| CVE-2021-34790 | 4.7 MEDIUM | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Applicati |
| CVE-2021-34791 | 4.7 MEDIUM | Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Applicati |
| CVE-2021-34761 | 4.4 MEDIUM | Cisco Firepower Threat Defense Software CLI Arbitrary File Write Vulnerability |
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V. Comments for CVE-2021-34781
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