Medium severity · published Dec 6, 2023
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
5.3
CVSS
1.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
None
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.2% · higher than 68% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
GO
GO · Golang
before 1.20.12; 1.21.0-0 before 1.21.5 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-39326
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-39326
Patch
https://go.dev/cl/547335
Issue Tracking
https://go.dev/issue/64433
Mailing List
https://groups.google.com/g/golang-dev/c/6ypN5EjibjM/m/KmLVYH_uAgAJ
lists.fedoraproject.org
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/UIU6HOGV6RRIKWM57LOXQA75BGZSIH6G/
Patch
https://pkg.go.dev/vuln/GO-2023-2382
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