9.8

CVE-2023-48230

Exploit

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.

Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Capnproto ≫ Capnproto Version1.0.0
Capnproto ≫ Capnproto Version1.0.1
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 4.16% 0.88
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 9.8 3.9 5.9
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
security-advisories@github.com 5.9 2.2 3.6
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE-124 Buffer Underwrite ('Buffer Underflow')

The product writes to a buffer using an index or pointer that references a memory location prior to the beginning of the buffer.

CWE-787 Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.