CVE-2021-27877 Veritas Backup Exec Agent: login or permission bypass
In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.
Confirmed exploited by CISA on · US federal patch deadline Apr 28, 2023
What to do
- Install Veritas's security update for Backup Exec Agent. If no update exists, follow the vendor's workaround or stop using the product until one ships.
- Keep a list of every internet-facing server you run so nothing is forgotten.
- Patch anything in this catalog first, ahead of normal patch cycles.
- Put admin and file-transfer apps behind a VPN or single sign-on instead of the open internet.
Who is affected
Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.
What's at risk: Mass data theft and ransomware: a single flaw in a file-transfer or email server has exposed thousands of organisations at once.
The details
- Official name
- Veritas Backup Exec Agent Improper Authentication Vulnerability
- Product
- Veritas Backup Exec Agent
- CISA description
- Veritas Backup Exec (BE) Agent contains an improper authentication vulnerability that could allow an attacker unauthorized access to the BE Agent via SHA authentication scheme.
- Type of flaw
- Login or permission bypass (CWE-287)
- Confirmed exploited
- Apr 7, 2023 — known to be used in ransomware attacks
- US federal patch deadline
- Apr 28, 2023
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Answering about CVE-2021-27877 ·
Questions about CVE-2021-27877
Is CVE-2021-27877 being exploited?
Yes. CISA added CVE-2021-27877 to its Known Exploited Vulnerabilities catalog on Apr 7, 2023, which means there is reliable evidence of real-world attacks, including by ransomware groups.
How do I fix CVE-2021-27877?
Install Veritas's security update for Backup Exec Agent. If no update exists, follow the vendor's workaround or stop using the product until one ships. Keep a list of every internet-facing server you run so nothing is forgotten.
Am I affected by CVE-2021-27877?
Only if you use Veritas Backup Exec Agent. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.