Wasmtime: Leak in WASIp1 `fd_renumber` implementation
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 24.0.10, 36.0.11, 44.0.3, 45.0.2
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
- Exploitation: none
- Automatable: no
- Technical impact: partial
Summary
Wasmtime is a runtime for WebAssembly. All versions prior to 24.0.10; versions 25.0.0 through those before 36.0.11; versions 37.0.0 through those before 44.0.3; and versions 45.0.0 and 45.0.1 contain a native implementation of WASIp1 which suffers from a leak in the fd_renumber function where the file descriptor being renumbered to is not properly closed. Wasmtime's implementation erroneously only updated the table of descriptors for WASIp1 and didn't update the underlying table of descriptors used by the host. This behavior means that while fd_renumber works correctly from a guest's perspective it ends up leaking resources in the host that aren't cleaned up until the corresponding Store is destroyed. In a loop, guests can use fd_renumber to cause hosts to exhaust both resources and file descriptors. This bug only affects the native implementation of WASIp1, meaning that only runtimes which load core wasm modules and expose fd_renumber are affected. Runtimes are additionally only affected if they expose the ability to acquire a file descriptor, such as opening a file. For runtimes that deny access to files they are unaffected. This issue has been fixed in versions 24.0.10, 36.0.11, 44.0.3, and 45.0.2.
Timeline
- CVE published
- CISA SSVC assessment
Exploitation: none · Automatable: no · Technical impact: partial
- Record last updated
Affected versions
- bytecodealliance wasmtime
fixed in 24.0.10; From 25.0.0 · fixed in 36.0.11; From 37.0.0 · fixed in 44.0.3; From 45.0.0 · fixed in 45.0.2
- wasmtime-wasicrates.io
fixed in 24.0.10
- wasmtime-wasicrates.io
From 45.0.0 · fixed in 45.0.2
- wasmtime-wasicrates.io
From 25.0.0 · fixed in 36.0.11
- wasmtime-wasicrates.io
From 37.0.0 · fixed in 44.0.3
- wasmtime-wasicrates.io
From 0.0.0-0 · fixed in 24.0.10; From 25.0.0 · fixed in 36.0.11; From 37.0.0 · fixed in 44.0.3; From 45.0.0 · fixed in 45.0.2