CVE-2021-27878
Veritas — Veritas Backup Exec Agent Command Execution Vulnerability
Veritas · Not classified by connected sources · in CISA KEV since 2023-04-07
EVRS 75 of 100 Urgent
Patch This Cycle
Rank 873 of 2,960 tracked
Raised to the floor for a confirmed exploited vulnerability.
Why it scores 75
Evidence available: 6 of 7 signalsListed in the CISA KEV catalog, and associated with known ransomware campaigns.
- CISA KEVApplied
- RansomwareApplied
- Vendor exploitationDid not apply
- EPSSApplied
- Microsoft Exploitability IndexNot applicable
- Pre-patch disclosureNo data
- KEV recencyDid not apply
- CVSSApplied
The band answers “how soon”, not “how bad”. No data for: Pre-patch disclosure. Why some signals show no data
Fix
Patch or fixed version identifiedCISA required action
Fixed in
backup exec: update to 21.2 or later
Affected versions
- backup exec
< 21.2
Remediation
Apply updates per vendor instructions.
Fixed versions from NVD.
Evidence
Each value with its source| Measure | Value | Source |
|---|---|---|
| CVSS base scoreHow severe the flaw is in itself. It does not say how likely an attack is. | 8.8 | NVD |
| FIRST EPSSFIRST's estimate of the chance this is exploited in the next 30 days, and how that ranks against all CVEs. | 0.240 (97.8th pctl) | FIRST EPSS |
| Actively exploitedWhether a source of record has confirmed attacks using it in the wild. | Confirmed | CISA KEV |
| Ransomware campaign useWhether CISA has seen ransomware operators use it. | Known | CISA KEV |
| CISA remediation deadlineThe date US federal agencies must have fixed or mitigated it. | 2023-04-28 · KEV since 2023 · listed over a year | CISA KEV |
| Public exploit moduleA module existing is not the same as active exploitation. | Public module exists | Metasploit |
| EUVD cross-referenceENISA's record: CVSS 8.8 (v3.1), assigned by mitre. | Listed | ENISA EUVD |
Description
NVDAn 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. The attacker could use one of these commands to execute an arbitrary command on the system using system privileges.
What CISA says to do
Public module
Metasploit lists a public excellent-rank module for this CVE: Veritas Backup Exec Agent Remote Code Execution (multi/veritas/beagent_sha_auth_rce). A module existing is not the same as active exploitation; see metasploit.com.