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Fencer Vulns
high 8.8

CVE-2021-1284 json

Cisco SD-WAN vManage Software Authentication Bypass Vulnerability

published 2021-05-06 5 y ago modified 2026-06-17 4 mo ago also EUVD-2021-6751

cvss
8.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.4%
EPSS 0.4% chance of exploitation in 30 days, percentile 38%
public exploits
0
none known

Summary

A vulnerability in the web-based messaging service interface of Cisco SD-WAN vManage Software could allow an unauthenticated, adjacent attacker to bypass authentication and authorization and modify the configuration of an affected system. To exploit this vulnerability, the attacker must be able to access an associated Cisco SD-WAN vEdge device. This vulnerability is due to insufficient authorization checks. An attacker could exploit this vulnerability by sending crafted HTTP requests to the web-based messaging service interface of an affected system. A successful exploit could allow the attacker to gain unauthenticated read and write access to the affected vManage system. With this access, the attacker could access information about the affected vManage system, modify the configuration of the system, or make configuration changes to devices that are managed by the system.

Patch / fix

  • cisco catalyst_sd-wan_manager 20.4.1, 20.5.1
  • cisco sd-wan_vmanage 20.3.1

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 y ago

Exploit prediction

0.44% chance of exploitation in the next 30 days, higher than 38% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 8.8 CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 5.8 AV:A/AC:L/Au:N/C:P/I:P/A:P

Affected products

  • Cisco Cisco SD-WAN vManage

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.