SB2026082167 - Multiple vulnerabilities in Wasmtime

Description

This security bulletin contains information about 2 vulnerabilities.

1) Uncontrolled Memory Allocation (CVE-ID: N/A)

CWE-ID: CWE-789 - Uncontrolled Memory Allocation

CVSSv4: 6.8 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to cause a denial of service.

The vulnerability exists due to memory allocation with excessive size value in WASIp3 file and HTTP streams when writing to streams with a guest-specified-length buffer. A remote user can provide stream data with a guest-controlled length to cause a denial of service.

WASIp3 was not enabled by default in versions prior to 46.0.0. User interaction is required.

2) UNIX symbolic link following (CVE-ID: N/A)

CWE-ID: CWE-61 - UNIX Symbolic Link (Symlink) Following

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a remote user to access files and directories outside the intended filesystem sandbox.

The vulnerability exists due to unix symbolic link following in wasmtime-wasi filesystem sandboxing when processing paths or symlinks containing trailing slashes. A remote user can provide a crafted path or symlink reference to access files and directories outside the intended filesystem sandbox.

This issue does not affect environments using a Linux kernel newer than 5.6 with the openat2 syscall and the RESOLVE_BENEATH flag.

Remediation

Install update from vendor's website.

References

• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-x84v-gj2h-g759
• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-vqjp-4c8c-hfgg