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CVE-2021-40346

HIGHCVSS 7.5/10EPSS 56.08%

Last modified

CVE-2021-40346 is a high-severity vulnerability rated 7.5/10 on the CVSS scale. An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs.. EPSS estimates a 56.08% chance of exploitation in the next 30 days.

Description

An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs.

Metrics

CVSS 3.1
7.5/10

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

EPSS Probability
56.08%

98.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
HaproxyHaproxy>= 2.0.0, < 2.0.25—
HaproxyHaproxy>= 2.2.0, < 2.2.17—
HaproxyHaproxy>= 2.3.0, < 2.3.14—
HaproxyHaproxy>= 2.4.0, < 2.4.4—
HaproxyHaproxy2.5Dev0
DebianDebian Linux11.0—
FedoraprojectFedora33—
FedoraprojectFedora34—

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2021-40346?
An integer overflow exists in HAProxy 2.0 through 2.5 in htx_add_header that can be exploited to perform an HTTP request smuggling attack, allowing an attacker to bypass all configured http-request HAProxy ACLs and possibly other ACLs.
How severe is CVE-2021-40346?
CVE-2021-40346 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 56.08% probability of exploitation in the next 30 days.
How do I fix CVE-2021-40346?
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.

Are you affected by CVE-2021-40346?

Run a free Strix scan to check your systems for this vulnerability.

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Source: NVD / NIST