CVE-2025-43970

MRT parser crash via truncated BGP4MP headers

Published Apr 21, 2025 · Updated Apr 21, 2025

Improper length validation in GoBGP before 3.35.0 allows local users to interrupt MRT parsing with truncated BGP4MP records. BGP4MPHeader.decodeFromBytes checks only enough bytes for AS fields, then slices interface, address-family, and IP-address fields without verifying the required remaining bytes. Processing crafted MRT data triggers an out-of-range panic in the consuming process; network reachability alone does not expose this file-oriented parser.

CVSS severity4.3
Medium
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Improper length validation in GoBGP before 3.35.0 allows local users to interrupt MRT parsing with truncated BGP4MP records. BGP4MPHeader.decodeFromBytes checks only enough bytes for AS fields, then slices interface, address-family, and IP-address fields without verifying the required remaining bytes. Processing crafted MRT data triggers an out-of-range panic in the consuming process; network reachability alone does not expose this file-oriented parser.

The record

CVE
CVE-2025-43970
Published
Apr 21, 2025
Updated
Apr 21, 2025
Vendor
GoBGP
Product
GoBGP
Classifications
CWE-1284, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 21, 2025CVE publishedPublication date reported by the CVE source.
  2. Apr 21, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.35.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

GoBGP · GoBGPversion=0 <3.35.0

Published CVSS scores

5.3NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
4.3MITRECVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-1284Improper Validation of Specified Quantity in Input
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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