CVE-2024-53259: quic-go is an implementation of the QUIC protocol in Go. An off-path attacker can inject an ICMP Packet Too Large packet. Since affected quic-go versi...

Description

quic-go is an implementation of the QUIC protocol in Go. An off-path attacker can inject an ICMP Packet Too Large packet. Since affected quic-go versions used IP_PMTUDISC_DO, the kernel would then return a "message too large" error on sendmsg, i.e. when quic-go attempts to send a packet that exceeds the MTU claimed in that ICMP packet. By setting this value to smaller than 1200 bytes (the minimum MTU for QUIC), the attacker can disrupt a QUIC connection. Crucially, this can be done after completion of the handshake, thereby circumventing any TCP fallback that might be implemented on the application layer (for example, many browsers fall back to HTTP over TCP if they're unable to establish a QUIC connection). The attacker needs to at least know the client's IP and port tuple to mount an attack. This vulnerability is fixed in 0.48.2.

Metrics

CVSS 3.1

6.5/10

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

EPSS Probability

0.60%

44.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-345

References

Timeline

Published: Dec 2, 2024
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2024-53259?

quic-go is an implementation of the QUIC protocol in Go. An off-path attacker can inject an ICMP Packet Too Large packet. Since affected quic-go versions used IP_PMTUDISC_DO, the kernel would then return a "message too large" error on sendmsg, i.e. when quic-go attempts to send a packet that exceeds the MTU claimed in that ICMP packet. By setting this value to smaller than 1200 bytes (the minimum MTU for QUIC), the attacker can disrupt a QUIC connection. Crucially, this can be done after completion of the handshake, thereby circumventing any TCP fallback that might be implemented on the application layer (for example, many browsers fall back to HTTP over TCP if they're unable to establish a QUIC connection). The attacker needs to at least know the client's IP and port tuple to mount an attack. This vulnerability is fixed in 0.48.2.

How severe is CVE-2024-53259?

CVE-2024-53259 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.60% probability of exploitation in the next 30 days.

How do I fix CVE-2024-53259?

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.