CVE-2021-20021
Published: November 3, 2021
Official Description
SonicWall Email Security contains an improper privilege management vulnerability that allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20022 and CVE-2021-20023 to achieve privilege escalation.
CISA KEV Advisory
SonicWall Email Security Improper Privilege Management Vulnerability
SonicWall Email Security contains an improper privilege management vulnerability that allows an attacker to create an administrative account by sending a crafted HTTP request to the remote host. This vulnerability has known usage in a SonicWall Email Security exploit chain along with CVE-2021-20022 and CVE-2021-20023 to achieve privilege escalation.
Apply updates per vendor instructions.
Risk Analysis
This vulnerability in SonicWall Email Security allows an attacker to create an administrative account by sending a specially crafted HTTP request. This is a high-severity flaw with a very high EPSS score of 0.91741, indicating a high likelihood of exploitation, and it is confirmed to be exploited in the wild.
Active exploitation of this vulnerability has been observed in the wild. It is known to be part of an exploit chain to achieve privilege escalation.
Administrators should apply the latest security updates for SonicWall Email Security to address this improper privilege management vulnerability.
Technical Analysis
CVE-2021-20021 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
CISA has added CVE-2021-20021 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.
Exploit & PoC Resources
All References (1)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2021-20021 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts
- !CISA KEV: Federal agencies must patch per BOD 22-01 timeline
- !Active exploitation confirmed — treat as P1