ACL bypass via incorrect post-reload stack processing
Published Jan 26, 2024 · Updated Nov 13, 2024
ACL processing in Cisco Small Business switches with affected firmware allows remote attackers to bypass ACLs using crafted traffic. After a primary or backup switch undergoes a full stack reload or power cycle, the stacked configuration applies ACLs correctly on primary devices but can apply them incorrectly on backup devices. Exploitation requires ACLs on a stacked configuration and the vulnerable post-reload state, which attackers cannot trigger; affected backup devices can drop or forward traffic contrary to policy.
Summary
What happened
ACL processing in Cisco Small Business switches with affected firmware allows remote attackers to bypass ACLs using crafted traffic. After a primary or backup switch undergoes a full stack reload or power cycle, the stacked configuration applies ACLs correctly on primary devices but can apply them incorrectly on backup devices. Exploitation requires ACLs on a stacked configuration and the vulnerable post-reload state, which attackers cannot trigger; affected backup devices can drop or forward traffic contrary to policy.
The record
- CVE
- CVE-2024-20263
- Published
- Jan 26, 2024
- Updated
- Nov 13, 2024
- Vendor
- ClamAV
- Product
- Cisco Small Business Smart and Managed Switches
- Classifications
- CWE-284
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jan 26, 2024CVE publishedPublication date reported by the CVE source.
- Nov 13, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.0.0.73
- Affected versionversion=2.1.0.63
- Affected versionversion=2.2.0.63
- Affected versionversion=2.2.0.66
- Affected versionversion=2.2.5.68
- Affected versionversion=2.2.7.07
- Affected versionversion=2.2.8.04
- Affected versionversion=2.3.0.130
- Affected versionversion=2.3.5.63
- Affected versionversion=2.4.0.91
- Affected versionversion=2.4.0.94
- Affected versionversion=2.4.5.71
- Affected versionversion=2.5.0.78
- Affected versionversion=2.5.0.79
- Affected versionversion=2.5.0.82
- Affected versionversion=2.5.0.83
- Affected versionversion=2.5.0.89
- Affected versionversion=2.5.0.90
- Affected versionversion=2.5.0.92
- Affected versionversion=2.5.5.47
- Affected versionversion=2.5.7.85
- Affected versionversion=2.5.8.12
- Affected versionversion=2.5.8.15
- Affected versionversion=2.5.9.13
- Affected versionversion=2.5.9.15
- Affected versionversion=2.5.9.16
- Affected versionversion=3.0.0.61
- Affected versionversion=3.0.0.69
- Affected versionversion=3.1.0.57
- Affected versionversion=3.1.1.7
- Affected versionversion=3.2.0.84
- Affected versionversion=3.2.0.89
- Affected versionversion=3.2.1.1
- Affected versionversion=3.3.0.16
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo