What’s Vulnerable › Vulnerabilities
CVE-2021-34739: Cisco Small Business Series Switches Session Credentials Replay Vulnerability
- Severity: high (CVSS 8.1 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.7% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2021-11-04 · updated 2026-06-17
- Weakness: CWE-613
Description
A vulnerability in the web-based management interface of multiple Cisco Small Business Series Switches could allow an unauthenticated, remote attacker to replay valid user session credentials and gain unauthorized access to the web-based management interface of an affected device. This vulnerability is due to insufficient expiration of session credentials. An attacker could exploit this vulnerability by conducting a man-in-the-middle attack against an affected device to intercept valid session credentials and then replaying the intercepted credentials toward the same device at a later time. A successful exploit could allow the attacker to access the web-based management interface with administrator privileges.
Affected products
- Cisco Cbs250-16P-2G Firmware: through 3.1
- Cisco Cbs250-16T-2G Firmware: through 3.1
- Cisco Cbs250-24Fp-4G Firmware: through 3.1
- Cisco Cbs250-24Fp-4X Firmware: through 3.1
- Cisco Cbs250-24P-4G Firmware: through 3.1
- Cisco Cbs250-24P-4X Firmware: through 3.1
- Cisco Cbs250-24Pp-4G Firmware: through 3.1
- Cisco Cbs250-24T-4G Firmware: through 3.1
- Cisco Cbs250-24T-4X Firmware: through 3.1
- Cisco Cbs250-48P-4G Firmware: through 3.1
- Cisco Cbs250-48P-4X Firmware: through 3.1
- Cisco Cbs250-48Pp-4G Firmware: through 3.1
- Cisco Cbs250-48T-4G Firmware: through 3.1
- Cisco Cbs250-48T-4X Firmware: through 3.1
- Cisco Cbs250-8Fp-E-2G Firmware: through 3.1
- Cisco Cbs250-8P-E-2G Firmware: through 3.1
- Cisco Cbs250-8Pp-D Firmware: through 3.1
- Cisco Cbs250-8Pp-E-2G Firmware: through 3.1
- Cisco Cbs250-8T-D Firmware: through 3.1
- Cisco Cbs250-8T-E-2G Firmware: through 3.1
- Cisco Cbs350-12Np-4X Firmware: through 3.1
- Cisco Cbs350-12Xs Firmware: through 3.1
- Cisco Cbs350-12Xt Firmware: through 3.1
- Cisco Cbs350-16Fp-2G Firmware: through 3.1
- Cisco Cbs350-16P-2G Firmware: through 3.1
- Cisco Cbs350-16P-E-2G Firmware: through 3.1
- Cisco Cbs350-16T-2G Firmware: through 3.1
- Cisco Cbs350-16T-E-2G Firmware: through 3.1
- Cisco Cbs350-16Xts Firmware: through 3.1
- Cisco Cbs350-24Fp-4G Firmware: through 3.1
References
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-smb-switches-tokens-UzwpR4e5
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-smb-switches-tokens-UzwpR4e5
Get alerted when CVE-2021-34739 or the next vulnerability affects your stack