PT-2022-24951 · Wasmtime · Wasmtime

Alexcrichton · Published 2022-11-05 · Updated 2023-06-27 · CVE-2022-39392

Positive Technologies (AI Summary)

CVSS v3.1

5.9

Medium

Base vector

AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N

Name of the Vulnerable Software and Affected Versions Wasmtime versions prior to 2.0.2

Description There is a bug in Wasmtime's implementation of its pooling instance allocator when the allocator is configured to give WebAssembly instances a maximum of zero pages of memory. In this configuration, the virtual memory mapping for WebAssembly memories did not meet the compiler-required configuration requirements for safely executing WebAssembly modules. Wasmtime's default settings require virtual memory page faults to indicate that wasm reads/writes are out-of-bounds, but the pooling allocator's configuration would not create an appropriate virtual memory mapping for this, meaning out of bounds reads/writes can successfully read/write memory unrelated to the wasm sandbox within range of the base address of the memory mapping created by the pooling allocator. This bug can only be triggered by setting InstanceLimits::memory pages to zero. This is expected to be a very rare configuration since this means that wasm modules cannot allocate any pages of linear memory. All wasm modules produced by all current toolchains are highly likely to use linear memory, so it's expected to be unlikely that this configuration is set to zero by any production embedding of Wasmtime.

Recommendations To resolve the issue, upgrade to Wasmtime 2.0.2. As a temporary workaround, consider increasing the memory pages allotment when configuring the pooling allocator to a value greater than zero. If an embedding wishes to still prevent memory from actually being used, then the Store::limiter method can be used to dynamically disallow growth of memory beyond 0 bytes large. Note that the default memory pages value is greater than zero.

Exploit

Fix

Buffer Overflow

Out of bounds Read

Memory Corruption

Weakness Enumeration

CWE-119

CWE-125

CWE-787

Related Identifiers

CVE-2022-39392

GHSA-44MR-8VMM-WJHG

RUSTSEC-2022-0076

RUSTSEC-2022-0102

Affected Products

Wasmtime

References · 18

• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/39xxx/CVE-2022-39392.json · Exploit
• https://github.com/bytecodealliance/wasmtime/commit/e60c3742904ccbb3e26da201c9221c38a4981d72 · Patch
• https://osv.dev/vulnerability/RUSTSEC-2022-0102 · Vendor Advisory
• https://osv.dev/vulnerability/UBUNTU-CVE-2022-39392 · Vendor Advisory
• https://cve.org/CVERecord?id=CVE-2022-39392 · Security Note
• https://ubuntu.com/security/CVE-2022-39392 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2022-39392 · Security Note
• https://osv.dev/vulnerability/RUSTSEC-2022-0076 · Vendor Advisory
• https://osv.dev/vulnerability/GHSA-44mr-8vmm-wjhg · Vendor Advisory
• https://osv.dev/vulnerability/CVE-2022-39392 · Vendor Advisory
• https://github.com/bytecodealliance/wasmtime · Note
• https://github.com/bytecodealliance/wasmtime/security/advisories/GHSA-44mr-8vmm-wjhg · Note
• https://t.me/cvenotify/53166 · Telegram Post
• https://rustsec.org/advisories/RUSTSEC-2022-0102.html · Note
• https://rustsec.org/advisories/RUSTSEC-2022-0076.html · Note