Spring For Apache Kafka: Deserialization of Untrusted Data
CVE-2023-34040 is a high-severity deserialization of untrusted data vulnerability in Spring For Apache Kafka from Spring, 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 2.9.11, 3.0.10 as the first without the flaw, so updating Spring For Apache Kafka to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 2.09% chance of exploitation within 30 days, higher than 82% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Spring For Apache Kafka to 2.9.11 or 3.0.10, whichever matches your release line, or a later version.
- Read the advisory on spring.io for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Spring | Spring For Apache Kafka | 2.8.x up to, but not including, 2.9.11; 2.9.x up to, but not including, 2.9.11; 3.0.x up to, but not including, 3.0.10 | 2.9.11, 3.0.10 |
Version data comes from the organisation that assigned the CVE. 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 | 5.3 | Medium | CNA (vmware.com) |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In Spring for Apache Kafka 3.0.9 and earlier and versions 2.9.10 and earlier, a possible deserialization attack vector existed, but only if unusual configuration was applied. An attacker would have to construct a malicious serialized object in one of the deserialization exception record headers. Specifically, an application is vulnerable when all of the following are true: * The user does not configure an ErrorHandlingDeserializer for the key and/or value of the record * The user explicitly sets container properties checkDeserExWhenKeyNull and/or checkDeserExWhenValueNull container properties to true. * The user allows untrusted sources to publish to a Kafka topic By default, these properties are false, and the container only attempts to deserialize the headers if an ErrorHandlingDeserializer is configured. The ErrorHandlingDeserializer prevents the vulnerability by removing any such malicious headers before processing the record.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
- spring.io/security/cve-2023-34040Mitigation
Other vulnerabilities in Spring For Apache Kafka
- 8.1 High severity
Recent Deserialization of Untrusted Data vulnerabilities
- 8.8 High severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
- 9.8 Critical severity
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