Firewall bypass via trusted-binary DLL side-loading
Published Sep 24, 2021 · Updated Aug 3, 2024
Firewall bypass in Dr.Web Security Space 12.5.2.4160 on Windows allows local users to send blocked traffic through a trusted process. The frwl_svc.exe binary loads a user-supplied version.dll from its working directory, while the firewall exempts traffic originating from Dr.Web-signed applications. A local user must copy the signed binary beside the payload DLL and launch it; the bypass permits outbound connections and command traffic without granting higher process privileges.
Summary
What happened
Firewall bypass in Dr.Web Security Space 12.5.2.4160 on Windows allows local users to send blocked traffic through a trusted process. The frwl_svc.exe binary loads a user-supplied version.dll from its working directory, while the firewall exempts traffic originating from Dr.Web-signed applications. A local user must copy the signed binary beside the payload DLL and launch it; the bypass permits outbound connections and command traffic without granting higher process privileges.
The record
- CVE
- CVE-2021-28130
- Published
- Sep 24, 2021
- Updated
- Aug 3, 2024
- Vendor
- Unknown vendor
- Product
- Unknown product
- Classifications
- CWE-427, T1574.002
- Attack vector
- local
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 24, 2021CVE publishedPublication date reported by the CVE source.
- Aug 3, 2024Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
What conditions does exploitation require?
What is affected?
Affected products and versions are unavailable in this record.
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.
Public exploit references
- Dr.Web Security Space 12 firewall-bypass demonstrationproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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