Cryptographic flaw in Cisco Firepower System Software
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · None
- Fix status
- No fix listed
Attack profile from CVSS 3.0 · NVD. Fix status from CNA.
Summary
A vulnerability in the Secure Sockets Layer (SSL) Decryption and Inspection feature of Cisco Firepower System Software 5.4.0, 5.4.1, 6.0.0, 6.1.0, 6.2.0, 6.2.1, and 6.2.2 could allow an unauthenticated, remote attacker to bypass the SSL policy for decrypting and inspecting traffic on an affected system. The vulnerability is due to unexpected interaction with Known Key and Decrypt and Resign configuration settings of SSL policies when the affected software receives unexpected SSL packet headers. An attacker could exploit this vulnerability by sending a crafted SSL packet through an affected device in a valid SSL session. A successful exploit could allow the attacker to bypass the SSL decryption and inspection policy for the affected system, which could allow traffic to flow through the system without being inspected. Cisco Bug IDs: CSCve12652.
Why it matters now
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| — | Cisco Firepower System Software | Cisco Firepower System Software | — | No fix listed | CNA |
- Cisco Firepower System Software Vendor— Affected Cisco Firepower System Software Fixed in — No fix listed CNA
CPE configurations NVD · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:cisco:firesight_system_software:5.4.0:*:*:*:*:*:*:* | 5.4.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:firesight_system_software:5.4.1:*:*:*:*:*:*:* | 5.4.1 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:firesight_system_software:6.0.0:*:*:*:*:*:*:* | 6.0.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:firesight_system_software:6.1.0:*:*:*:*:*:*:* | 6.1.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:firesight_system_software:6.2.0:*:*:*:*:*:*:* | 6.2.0 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:firesight_system_software:6.2.1:*:*:*:*:*:*:* | 6.2.1 | Vulnerable | Cisco |
| cpe:2.3:a:cisco:firesight_system_software:6.2.2:*:*:*:*:*:*:* | 6.2.2 | Vulnerable | Cisco |
- cpe:2.3:a:cisco:firesight_system_software:5.4.0:*:*:*:*:*:*:* Versions 5.4.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:firesight_system_software:5.4.1:*:*:*:*:*:*:* Versions 5.4.1 Vulnerable ·Cisco
- cpe:2.3:a:cisco:firesight_system_software:6.0.0:*:*:*:*:*:*:* Versions 6.0.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:firesight_system_software:6.1.0:*:*:*:*:*:*:* Versions 6.1.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:firesight_system_software:6.2.0:*:*:*:*:*:*:* Versions 6.2.0 Vulnerable ·Cisco
- cpe:2.3:a:cisco:firesight_system_software:6.2.1:*:*:*:*:*:*:* Versions 6.2.1 Vulnerable ·Cisco
- cpe:2.3:a:cisco:firesight_system_software:6.2.2:*:*:*:*:*:*:* Versions 6.2.2 Vulnerable ·Cisco
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2017-6766
- 2026-10-03 Alias added: GHSA-q3pq-v78p-xj7q
References
More Cisco Firesight System Software vulnerabilities
- TI-2015-05322 The policy implementation in Cisco FireSIGHT Management Center 5.3.1.7, 5.4.0.4, and… CVSS 2.0HIGH 9.0
- TI-2016-05477 Session fixation vulnerability in Cisco Firepower Management Center and Cisco FireSIGHT… CVSS 3.0CRITICAL 9.1
- TI-2016-05499 Cross-site request forgery (CSRF) vulnerability in Cisco FireSIGHT System Software 4.10.2… CVSS 3.0HIGH 8.8
- TI-2016-01285 Cisco Firepower System Software 6.0.0 through 6.1.0 has a hardcoded account, which allows… CVSS 3.0HIGH 8.6
- TI-2016-07522 Improper input validation in Cisco FireSIGHT CVSS 3.0HIGH 7.5
- TI-2016-01351 Cisco FireSIGHT System Software 5.3.0, 5.3.1, 5.4.0, 6.0, and 6.0.1 allows remote… CVSS 3.0HIGH 7.5
Sources
- CVE-2017-6766 · CVE Program
- CVE-2017-6766 · NVD
- FIRST EPSS
- GHSA-q3pq-v78p-xj7q · GitHub Advisory Database · CC BY 4.0
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