Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.4, 33.0.2, and 34.0.2, a bug in Wasmtime's implementation of the WASIp1 set of import functions can lead to a WebAssembly guest inducing a panic in the host (embedder). The specific bug is triggered by calling `path_open` after calling `fd_renumber` with either two equal argument values or a second argument being equal to a previously-closed file descriptor number value. The corrupt state introduced in `fd_renumber` will lead to the subsequent opening of a file descriptor to panic. This panic cannot introduce memory unsafety or allow WebAssembly to break outside of its sandbox, however. There is no possible heap corruption or memory unsafety from this panic. This bug is in the implementation of Wasmtime's `wasmtime-wasi` crate which provides an implementation of WASIp1. The bug requires a specially crafted call to `fd_renumber` in addition to the ability to open a subsequent file descriptor. Opening a second file descriptor is only possible when a preopened directory was provided to the guest, and this is common amongst embeddings. A panic in the host is considered a denial-of-service vector for WebAssembly embedders and is thus a security issue in Wasmtime. This bug does not affect WASIp2 and embedders using components. In accordance with Wasmtime's release process, patch releases are available as 24.0.4, 33.0.2, and 34.0.2. Users of other release of Wasmtime are recommended to move to a supported release of Wasmtime. Embedders who are using components or are not providing guest access to create more file descriptors (e.g. via a preopened filesystem directory) are not affected by this issue. Otherwise, there is no workaround at this time, and affected embeddings are recommended to update to a patched version which will not cause a panic in the host.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Wasmtime is a runtime for WebAssembly. Prior to versions 24.0.4, 33.0.2, and 34.0.2, a bug in Wasmtime's     implementation of the WASIp1 set of import functions can lead to a WebAssembly guest inducing a panic in     the host (embedder). The specific bug is triggered by calling `path_open` after calling `fd_renumber` with     either two equal argument values or a second argument being equal to a previously-closed file descriptor     number value. The corrupt state introduced in `fd_renumber` will lead to the subsequent opening of a file     descriptor to panic. This panic cannot introduce memory unsafety or allow WebAssembly to break outside of     its sandbox, however. There is no possible heap corruption or memory unsafety from this panic. This bug is     in the implementation of Wasmtime's `wasmtime-wasi` crate which provides an implementation of WASIp1. The     bug requires a specially crafted call to `fd_renumber` in addition to the ability to open a subsequent     file descriptor. Opening a second file descriptor is only possible when a preopened directory was provided     to the guest, and this is common amongst embeddings. A panic in the host is considered a denial-of-service     vector for WebAssembly embedders and is thus a security issue in Wasmtime. This bug does not affect WASIp2     and embedders using components. In accordance with Wasmtime's release process, patch releases are     available as 24.0.4, 33.0.2, and 34.0.2. Users of other release of Wasmtime are recommended to move to a     supported release of Wasmtime. Embedders who are using components or are not providing guest access to     create more file descriptors (e.g. via a preopened filesystem directory) are not affected by this issue.
    Otherwise, there is no workaround at this time, and affected embeddings are recommended to update to a     patched version which will not cause a panic in the host. (CVE-2025-53901)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the 605a9d1e-6521-11f0-beb2-ac5afc632ba3 advisory.

    WasmTime development team reports:
    A bug in Wasmtime's implementation of the WASIp1 set of import               functions can lead to a WebAssembly guest inducing a panic in the               host (embedder).

Tenable has extracted the preceding description block directly from the FreeBSD security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
246230	Linux Distros Unpatched Vulnerability : CVE-2025-53901	Nessus	Misc.	low
242413	FreeBSD : libwasmtime -- host panic with fd_renumber WASIp1 function (605a9d1e-6521-11f0-beb2-ac5afc632ba3)	Nessus	FreeBSD Local Security Checks	low

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CVE-2025-53901

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