CVE-2021-27357Public exploitNetwork attack vector

Device crash via undersized RPL DAO packet

Published Apr 6, 2021 · Updated Aug 3, 2024

Buffer overflow in RIOT-OS 2020.01's GNRC RPL parser allows remote attackers to crash a device via a crafted ICMPv6 packet. gnrc_rpl_validation_DAO reads the k_d_flags field from an undersized packed DAO structure before confirming that the message contains that field. Exploitation requires the GNRC RPL module and network access able to deliver an RPL ICMPv6 DAO packet; the upstream reproduction demonstrates an out-of-bounds read and process abort.

CVSS severity9.8
Critical
EPSS probability1.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Buffer overflow in RIOT-OS 2020.01's GNRC RPL parser allows remote attackers to crash a device via a crafted ICMPv6 packet. gnrc_rpl_validation_DAO reads the k_d_flags field from an undersized packed DAO structure before confirming that the message contains that field. Exploitation requires the GNRC RPL module and network access able to deliver an RPL ICMPv6 DAO packet; the upstream reproduction demonstrates an out-of-bounds read and process abort.

The record

CVE
CVE-2021-27357
Published
Apr 6, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-120, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 6, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

9.8NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
7.5NIST NVDAV:N/AC:L/Au:N/C:P/I:P/A:P

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
T1499.004Application or System Exploitation

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo