Veeam: Deserialization of Untrusted Data
CVE-2022-26503 is a high-severity deserialization of untrusted data vulnerability in Veeam, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 4.0.2.2208, 5.0.3.4708 as the first without the flaw, so updating Veeam to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.69% chance of exploitation within 30 days, higher than 53% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Veeam to 4.0.2.2208 or 5.0.3.4708, whichever matches your release line, or a later version.
- Read the advisory on veeam.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Veeam | Veeam | 4.0.0 up to, but not including, 4.0.2.2208; 5.0.0 up to, but not including, 5.0.3.4708; 2.0; 2.1; 2.2; 3.0.2 | 4.0.2.2208, 5.0.3.4708 |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | NVD |
| CVSS 2.0 | 7.2 | High | NVD |
Official description
Deserialization of untrusted data in Veeam Agent for Windows 2.0, 2.1, 2.2, 3.0.2, 4.x, and 5.x allows local users to run arbitrary code with local system privileges.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Deserialization of Untrusted Data
The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.
How developers prevent this class of flaw
- If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
- When deserializing data, populate a new object rather than just deserializing. The result is that the data flows through safe input validation and that the functions are safe.
- Explicitly define a final object() to prevent deserialization.
More Deserialization of Untrusted Data vulnerabilities (CWE-502)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Advisories
Recent Deserialization of Untrusted Data vulnerabilities
- 9.8 Critical severity
- 8.8 High severity
- 7.2 High severity
- 7.2 High severity
- 7.5 High severity
- 8.8 High severity
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