Critical severity · published Mar 29, 2022
CVE-2021-42911
A Format String vulnerability exists in DrayTek Vigor 2960 <= 1.5.1.3, DrayTek Vigor 3900 <= 1.5.1.3, and DrayTek Vigor 300B <= 1.5.1.3 in the mainfunction.cgi file via a crafted…
9.8
CVSS
3.5%
EPSS
No
On KEV
Description
A Format String vulnerability exists in DrayTek Vigor 2960 <= 1.5.1.3, DrayTek Vigor 3900 <= 1.5.1.3, and DrayTek Vigor 300B <= 1.5.1.3 in the mainfunction.cgi file via a crafted HTTP message containing malformed QUERY STRING, which could let a remote malicious user execute arbitrary code.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)3.5% · higher than 89% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
VF
Vigor2960 Firmware · Draytek
through 1.5.1.3 · source: NVD
VF
Vigor300b Firmware · Draytek
through 1.5.1.3 · source: NVD
VF
Vigor3900 Firmware · Draytek
through 1.5.1.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2021-42911
CVE.org
https://www.cve.org/CVERecord?id=CVE-2021-42911
Exploit
https://gist.github.com/Cossack9989/e9c1c2d2e69b773ca4251acdd77f2835
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