jackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 2.18.11, 2.21.7, 2.22.3, 3.1.7, 3.2.3
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: poc
- Automatable: yes
- Technical impact: partial
Summary
TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: poc · Automatable: yes · Technical impact: partial
- Record last updated
Affected versions
- com.fasterxml.jackson.core:jackson-databind
From 2.0.0 · through 2.18.10; From 2.19.0 · through 2.21.6; From 2.22.0 · through 2.22.2
- tools.jackson.core:jackson-databind
From 3.0.0 · through 3.1.6; From 3.2.0 · through 3.2.2
- com.fasterxml.jackson.core:jackson-databindMaven
From 2.0.0 · fixed in 2.18.11
- com.fasterxml.jackson.core:jackson-databindMaven
From 2.19.0 · fixed in 2.21.7
- com.fasterxml.jackson.core:jackson-databindMaven
From 2.22.0 · fixed in 2.22.3
- tools.jackson.core:jackson-databindMaven
From 3.0.0 · fixed in 3.1.7
- tools.jackson.core:jackson-databindMaven
From 3.2.0 · fixed in 3.2.3