CVE-2018-10184: An issue was discovered in HAProxy before 1.8.8. The incoming H2 frame length was checked against the max_frame_size setting instead of being checked ...

Description

An issue was discovered in HAProxy before 1.8.8. The incoming H2 frame length was checked against the max_frame_size setting instead of being checked against the bufsize. The max_frame_size only applies to outgoing traffic and not to incoming, so if a large enough frame size is advertised in the SETTINGS frame, a wrapped frame will be defragmented into a temporary allocated buffer where the second fragment may overflow the heap by up to 16 kB. It is very unlikely that this can be exploited for code execution given that buffers are very short lived and their addresses not realistically predictable in production, but the likelihood of an immediate crash is absolutely certain.

Metrics

EPSS Probability

8.43%

94.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-119

Affected Software

Vendor	Product	Versions
Haproxy	Haproxy	< 1.8.8
Redhat	Enterprise Linux	7.0
Redhat	Enterprise Linux	7.3
Redhat	Enterprise Linux	7.4
Redhat	Enterprise Linux	7.5

References

Timeline

Published: May 9, 2018
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2018-10184?

An issue was discovered in HAProxy before 1.8.8. The incoming H2 frame length was checked against the max_frame_size setting instead of being checked against the bufsize. The max_frame_size only applies to outgoing traffic and not to incoming, so if a large enough frame size is advertised in the SETTINGS frame, a wrapped frame will be defragmented into a temporary allocated buffer where the second fragment may overflow the heap by up to 16 kB. It is very unlikely that this can be exploited for code execution given that buffers are very short lived and their addresses not realistically predictable in production, but the likelihood of an immediate crash is absolutely certain.

How severe is CVE-2018-10184?

Severity scoring for CVE-2018-10184 is pending analysis. The EPSS model estimates a 8.43% probability of exploitation in the next 30 days.

How do I fix CVE-2018-10184?

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.