High severity · published Jan 15, 2026
CVE-2021-47813
Backup Key Recovery 2.2.7 - Denial of Service (PoC)
7.5
CVSS
0.4%
EPSS
No
On KEV
Description
Backup Key Recovery 2.2.7 contains a denial of service vulnerability that allows attackers to crash the application by overflowing the registration code input field. Attackers can paste a large buffer of 256 repeated characters into the registration key field to trigger application instability and potential crash.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 34% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
BK
Backup Key Recovery · Nsauditor
2.2.7.0 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-47813
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-47813
www.nsauditor.com
http://www.nsauditor.com
www.exploit-db.com
https://www.exploit-db.com/exploits/49966
www.vulncheck.com
https://www.vulncheck.com/advisories/backup-key-recovery-denial-of-service-poc
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