Cisco Adaptive Security Appliance (ASA) Software: Missing Cryptographic Step
CVE-2022-20742 is a high-severity missing cryptographic step vulnerability in Cisco Adaptive Security Appliance (ASA) Software from Cisco, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Secure Firewall Threat Defense to 6.4.0.15 or 6.6.5.2 or 7.0.2, whichever matches your release line, or a later version.
- Update Adaptive Security Appliance Software to 9.12.4.38 or 9.14.4 or 9.15.1.21 or 9.16.2.14, whichever matches your release line, or a later version.
- Read the advisory on tools.cisco.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Adaptive Security Appliance (ASA) Software | Not specified in the record | Not stated |
| Cisco | Secure Firewall Threat Defense | before 6.4.0.15; 6.5.0 up to, but not including, 6.6.5.2; 7.0.0 up to, but not including, 7.0.2; 7.1.0 | 6.4.0.15, 6.6.5.2, 7.0.2 |
| Cisco | Adaptive Security Appliance Software | before 9.12.4.38; 9.13.0 up to, but not including, 9.14.4; 9.15.0 up to, but not including, 9.15.1.21; 9.16.0 up to, but not including, 9.16.2.14; 9.17.0 up to, but not including, 9.17.1.7 | 9.12.4.38, 9.14.4, 9.15.1.21, 9.16.2.14, 9.17.1.7 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.4 | High | CNA (cisco.com) |
| CVSS 3.1 | 7.4 | High | NVD |
| CVSS 2.0 | 5.8 | Medium | NVD |
Official description
A vulnerability in an IPsec VPN library of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to read or modify data within an IPsec IKEv2 VPN tunnel. This vulnerability is due to an improper implementation of Galois/Counter Mode (GCM) ciphers. An attacker in a man-in-the-middle position could exploit this vulnerability by intercepting a sufficient number of encrypted messages across an affected IPsec IKEv2 VPN tunnel and then using cryptanalytic techniques to break the encryption. A successful exploit could allow the attacker to decrypt, read, modify, and re-encrypt data that is transmitted across an affected IPsec IKEv2 VPN tunnel.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Missing Cryptographic Step
The product does not implement a required step in a cryptographic algorithm, resulting in weaker encryption than advertised by the algorithm.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in Cisco Adaptive Security Appliance (ASA) Software
- 9.0 Critical severity
- 8.6 High severity
- 8.6 High severity
- 8.5 High severity
- 7.7 High severity
- 8.6 High severity
Recent Missing Cryptographic Step vulnerabilities
- 7.5 High severity
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