CVE-2024-4435: When storing unbounded types in a BTreeMap, a node is represented as a linked list of "memory chunks". It was discovered recently that when we dealloc...

Description

When storing unbounded types in a BTreeMap, a node is represented as a linked list of "memory chunks". It was discovered recently that when we deallocate a node, in some cases only the first memory chunk is deallocated, and the rest of the memory chunks remain (incorrectly) allocated, causing a memory leak. In the worst case, depending on how a canister uses the BTreeMap, an adversary could interact with the canister through its API and trigger interactions with the map that keep consuming memory due to the memory leak. This could potentially lead to using an excessive amount of memory, or even running out of memory. This issue has been fixed in #212 https://github.com/dfinity/stable-structures/pull/212 by changing the logic for deallocating nodes to ensure that all of a node's memory chunks are deallocated and users are asked to upgrade to version 0.6.4.. Tests have been added to prevent regressions of this nature moving forward. Note: Users of stable-structure < 0.6.0 are not affected. Users who are not storing unbounded types in BTreeMap are not affected and do not need to upgrade. Otherwise, an upgrade to version 0.6.4 is necessary.

Metrics

CVSS 3.1

7.5/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS Probability

0.52%

39.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-401

Affected Software

Vendor	Product	Versions
Dfinity	Stable Structures	< 0.6.0

References

Timeline

Published: May 21, 2024
Last Modified: Jun 17, 2026
Status: Analyzed

Frequently Asked Questions

What is CVE-2024-4435?

When storing unbounded types in a BTreeMap, a node is represented as a linked list of "memory chunks". It was discovered recently that when we deallocate a node, in some cases only the first memory chunk is deallocated, and the rest of the memory chunks remain (incorrectly) allocated, causing a memory leak. In the worst case, depending on how a canister uses the BTreeMap, an adversary could interact with the canister through its API and trigger interactions with the map that keep consuming memory due to the memory leak. This could potentially lead to using an excessive amount of memory, or even running out of memory. This issue has been fixed in #212 https://github.com/dfinity/stable-structures/pull/212 by changing the logic for deallocating nodes to ensure that all of a node's memory chunks are deallocated and users are asked to upgrade to version 0.6.4.. Tests have been added to prevent regressions of this nature moving forward. Note: Users of stable-structure < 0.6.0 are not affected. Users who are not storing unbounded types in BTreeMap are not affected and do not need to upgrade. Otherwise, an upgrade to version 0.6.4 is necessary.

How severe is CVE-2024-4435?

CVE-2024-4435 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 0.52% probability of exploitation in the next 30 days.

How do I fix CVE-2024-4435?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.