CVE-2023-48230

Cap'n Proto is a data interchange format and capability-based RPC system. In versions 1.0 and 1.0.1, when using the KJ HTTP library with WebSocket compression enabled, a buffer underrun can be caused by a remote peer. The underrun always writes a constant value that is not attacker-controlled, likely resulting in a crash, enabling a remote denial-of-service attack. Most Cap'n Proto and KJ users are unlikely to have this functionality enabled and so unlikely to be affected. Maintainers suspect only the Cloudflare Workers Runtime is affected. If KJ HTTP is used with WebSocket compression enabled, a malicious peer may be able to cause a buffer underrun on a heap-allocated buffer. KJ HTTP is an optional library bundled with Cap'n Proto, but is not directly used by Cap'n Proto. WebSocket compression is disabled by default. It must be enabled via a setting passed to the KJ HTTP library via `HttpClientSettings` or `HttpServerSettings`. The bytes written out-of-bounds are always a specific constant 4-byte string `{ 0x00, 0x00, 0xFF, 0xFF }`. Because this string is not controlled by the attacker, maintainers believe it is unlikely that remote code execution is possible. However, it cannot be ruled out. This functionality first appeared in Cap'n Proto 1.0. Previous versions are not affected. This issue is fixed in Cap'n Proto 1.0.1.1.
Configurations

Configuration 1 (hide)

OR cpe:2.3:a:capnproto:capnproto:1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:capnproto:capnproto:1.0.1:*:*:*:*:*:*:*

History

29 Nov 2023, 02:35

Type Values Removed Values Added
CPE cpe:2.3:a:capnproto:capnproto:1.0.0:*:*:*:*:*:*:*
cpe:2.3:a:capnproto:capnproto:1.0.1:*:*:*:*:*:*:*
First Time Capnproto capnproto
Capnproto
CWE CWE-787
CVSS v2 : unknown
v3 : unknown
v2 : unknown
v3 : 9.8
References () https://github.com/capnproto/capnproto/security/advisories/GHSA-r89h-f468-62w3 - () https://github.com/capnproto/capnproto/security/advisories/GHSA-r89h-f468-62w3 - Exploit, Patch, Vendor Advisory
References () https://github.com/capnproto/capnproto/commit/75c5c1499aa6e7690b741204ff9af91cce526c59 - () https://github.com/capnproto/capnproto/commit/75c5c1499aa6e7690b741204ff9af91cce526c59 - Patch
References () https://github.com/capnproto/capnproto/commit/e7f22da9c01286a2b0e1e5fbdf3ec9ab3aa128ff - () https://github.com/capnproto/capnproto/commit/e7f22da9c01286a2b0e1e5fbdf3ec9ab3aa128ff - Patch

21 Nov 2023, 21:15

Type Values Removed Values Added
New CVE

Information

Published : 2023-11-21 21:15

Updated : 2023-12-10 15:26


NVD link : CVE-2023-48230

Mitre link : CVE-2023-48230

CVE.ORG link : CVE-2023-48230


JSON object : View

Products Affected

capnproto

  • capnproto
CWE
CWE-787

Out-of-bounds Write

CWE-124

Buffer Underwrite ('Buffer Underflow')