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CVE-2023-39326

MEDIUMCVSS 5.3/10EPSS 1.21%

Last modified

CVE-2023-39326 is a medium-severity vulnerability rated 5.3/10 on the CVSS scale. A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. EPSS estimates a 1.21% chance of exploitation in the next 30 days.

Description

A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.

Metrics

CVSS 3.1
5.3/10

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

EPSS Probability
1.21%

64.5th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

VendorProductVersions
GolangGo< 1.20.12
GolangGo>= 1.21.0-0, < 1.21.5

References

Timeline

Published
Last Modified
Status
Modified

Frequently Asked Questions

What is CVE-2023-39326?
A malicious HTTP sender can use chunk extensions to cause a receiver reading from a request or response body to read many more bytes from the network than are in the body. A malicious HTTP client can further exploit this to cause a server to automatically read a large amount of data (up to about 1GiB) when a handler fails to read the entire body of a request. Chunk extensions are a little-used HTTP feature which permit including additional metadata in a request or response body sent using the chunked encoding. The net/http chunked encoding reader discards this metadata. A sender can exploit this by inserting a large metadata segment with each byte transferred. The chunk reader now produces an error if the ratio of real body to encoded bytes grows too small.
How severe is CVE-2023-39326?
CVE-2023-39326 has a CVSS score of 5.3/10 (MEDIUM severity). The EPSS model estimates a 1.21% probability of exploitation in the next 30 days.
How do I fix CVE-2023-39326?
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-2023-39326?

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

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Source: NVD / NIST