CVE-2021-27876

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

The vulnerability is an authentication bypass in the SHA Authentication scheme used by Veritas Backup Exec prior to version 21.2. Although client-to-Agent communication is normally protected by TLS, a flaw in the scheme allows an attacker to complete the authentication process without valid credentials. Once authenticated, the client can issue data management protocol commands, and specially crafted parameters in one of those commands permit access to arbitrary files on the target system under System privileges.

An attacker with network access and low privileges can exploit the flaw remotely without user interaction. Successful exploitation grants the ability to read or write arbitrary files with full system rights, resulting in high confidentiality and integrity impact.

The vendor advisory VTS21-001 and associated references indicate that the issue is resolved in Backup Exec 21.2 and later. The vulnerability is also listed in CISA's Known Exploited Vulnerabilities catalog, and public proof-of-concept material for remote code execution has been published.

No additional real-world exploitation details or AI/ML relevance are provided in the source information.