CyberSecBulletin
CVE-2025-0755NVD status: Modified

libbson: Heap-based Buffer Overflow

Published Updated By the CyberSecBulletin desk

CVE-2025-0755 is a high-severity heap-based buffer overflow vulnerability in libbson from MongoDB, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists version 1.27.5 as the first without the flaw, so updating libbson to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.79% chance of exploitation within 30 days, higher than 57% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update libbson to 1.27.5 or a later version.
  2. Update MongoDB Server to 8.0.1 or 7.0.16, whichever matches your release line, or a later version.
  3. Update Mongodb to 7.0.16 or a later version.
  4. Read the advisory on jira.mongodb.org for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
MongoDBlibbsonbefore 1.27.51.27.5
MongoDBMongoDB Server8.0 up to, but not including, 8.0.1; 7.0 up to, but not including, 7.0.168.0.1, 7.0.16
MongoDBMongodb7.0.0 up to, but not including, 7.0.16; 8.0.07.0.16

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.18.4HighCNA (mongodb.com)
CVSS 3.17.5HighNVD

Official description

The various bson_append functions in the MongoDB C driver library may be susceptible to buffer overflow when performing operations that could result in a final BSON document which exceeds the maximum allowable size (INT32_MAX), resulting in a segmentation fault and possible application crash. This issue affected libbson versions prior to 1.27.5, MongoDB Server v8.0 versions prior to 8.0.1 and MongoDB Server v7.0 versions prior to 7.0.16

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Heap-based Buffer Overflow

The product writes past the end of a buffer that was allocated on the heap.

How developers prevent this class of flaw

  • Pre-design: Use a language or compiler that performs automatic bounds checking.
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Heap-based Buffer Overflow vulnerabilities (CWE-122)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Heap-based Buffer Overflow vulnerabilities

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