Known exploited vulnerability
CVE-2021-27876
The short answer
CVE-2021-27876 affects n/a n/a and is rated high (CVSS 8.1). CISA added it to the Known Exploited Vulnerabilities catalog on 2023-04-07: attackers are using it, so patch it first.
What it is
An issue was discovered in Veritas Backup Exec before 21.2. The communication between a client and an Agent requires successful authentication, which is typically completed over a secure TLS communication. However, due to a vulnerability in the SHA Authentication scheme, an attacker is able to gain unauthorized access and complete the authentication process. Subsequently, the client can execute data management protocol commands on the authenticated connection. By using crafted input parameters in one of these commands, an attacker can access an arbitrary file on the system using System privileges.
Severity
8.1 high
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Exploited (CISA KEV)
Yes, since Apr 7, 2023
Federal due date Apr 28, 2023
EPSS, next 30 days
14%
Higher than 96% of scored CVEs
How it can be exploited
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- None
What CISA says to do
Apply updates per vendor instructions.
Affected products
n/a. NVD's record lists the exact affected versions.
References
- www.veritas.com/content/support/en_US/security/VTS21-001#issue2 Vendor Advisory
- www.veritas.com/content/support/en_US/security/VTS21-001#issue2 Vendor Advisory
- www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-27876 US Government Resource
Questions
Is CVE-2021-27876 being exploited?
Yes. CISA added CVE-2021-27876 to its Known Exploited Vulnerabilities catalog on 2023-04-07, with a federal remediation due date of 2023-04-28. CISA lists it as used in ransomware campaigns.
How do I fix CVE-2021-27876?
CISA's required action: Apply updates per vendor instructions.
From NVD, CISA KEV, FIRST EPSS and OSV.dev, checked . Status on NVD: Analyzed. The description is NVD's text, quoted as published.
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