Security readout for executives and security teams
Plain-English summary
This CVE affects Veeam Backup and Replication versions before specific patched builds. The issue is mishandling of deserialization in Microsoft .NET remoting. Backup platforms are high-value operational systems, but the provided sources do not include CVSS, CWE, impact details, or proof of exploitation.
Executive priority
Prioritize confirmation and patching because backup infrastructure is business-critical. The urgency is driven by product role and deserialization risk, not by confirmed exploitation in the supplied sources.
Technical view
CVE-2021-35971 describes a .NET remoting deserialization handling flaw in Veeam Backup and Replication 10 before 10.0.1.4854 P20210609 and 11 before 11.0.0.837 P20210507. The source bundle does not provide attack prerequisites, affected components, privileges required, or technical impact beyond deserialization mishandling.
Likely exposure
Organizations running Veeam Backup and Replication 10 or 11 below the patched builds named in the CVE may be exposed. Exposure cannot be refined further from the supplied evidence because product configuration, reachable services, and component scope are not described.
Exploitation context
The source bundle does not show CISA KEV listing, public exploitation, exploit maturity, or weaponized activity. Treat active exploitation as unconfirmed based on the provided evidence.
Researcher notes
Evidence is thin. The CVE identifies affected version thresholds and .NET remoting deserialization mishandling, but lacks CVSS, CWE, affected component detail, exploitability conditions, or impact description. Use vendor KBs and local version checks as the primary validation path.
Mitigation direction
- Upgrade Veeam Backup and Replication 10 to 10.0.1.4854 P20210609 or later.
- Upgrade Veeam Backup and Replication 11 to 11.0.0.837 P20210507 or later.
- Review Veeam KB4126 and KB4180 for vendor-specific update guidance.
- Prioritize systems supporting backup, recovery, and disaster recovery operations.
Validation and detection
- Inventory Veeam Backup and Replication servers and record exact build numbers.
- Confirm no version 10 deployment is below 10.0.1.4854 P20210609.
- Confirm no version 11 deployment is below 11.0.0.837 P20210507.
- Document whether each backup server has completed the applicable Veeam update.
- Check vendor advisories for any environment-specific validation instructions.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CVE-2021-35971 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Unknown
- CVSS
- Not scored
- Known Exploited
- No
- Published
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS and timeline data
No CVSS vectors or timeline events were available in the normalized CVE source material.
Source materials
- CVE List V5 sourceCVE List V5
- https://www.veeam.com/kb4126CVE reference · x_refsource_MISC
- https://www.veeam.com/kb4180CVE reference · x_refsource_MISC
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.