rclone vulnerabilities

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.70.0 until 1.75.1, the serve/start RC interface accepts per-server proxyOpt.AuthProxy settings, and the FTP and S3 constructors in cmd/serve/ftp/ftp.go and cmd/serve/s3/server.go incorrectly check the process-global proxy.Opt.AuthProxy value instead. When the global value is empty, the request-local authentication proxy is ignored: FTP falls back to the fixed filesystem with username anonymous and any password, while S3 with AuthKey serves the fixed RC fs rather than the backend selected by the proxy. The dedicated command-line servers that configure the global option are not affected. This issue is fixed in version 1.75.1.

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.1, rclone serve s3 configured with --auth-proxy but without --auth-key allows authPairMiddleware to register any client-chosen accessKeyID with an empty ws.s3Secret. gofakes3 then verifies the request’s SigV4 signature against that same empty secret, while Server.auth passes the access key identifier as both the user and authentication value to the proxy without an independent per-identity secret. An unauthenticated network attacker can therefore choose an arbitrary access key, sign with an empty secret, and reach whatever backend the auth-proxy script resolves for that identity. This issue is fixed in version 1.75.1.

Rclone versions 1.46.0 through 1.74.2 have a vulnerability in server mode (rcd --rc-serve) that allows unauthenticated GET and HEAD requests to execute arbitrary system commands. An attacker can craft a URL containing remote storage configuration that executes local commands during initialization.

In Rclone from version 1.48.0 to 1.73.4, the RC endpoint `operations/fsinfo` is exposed without `AuthRequired: true` and accepts attacker-controlled `fs` input. An unauthenticated attacker can exploit this to execute arbitrary local commands on the server via the WebDAV backend, which runs `bearer_token_command` during initialization.

In Rclone, the RC endpoint `options/set` is exposed without `AuthRequired: true`, allowing modification of global runtime configuration. An unauthenticated attacker can set `rc.NoAuth=true`, disabling the authorization gate for many RC methods that normally require authentication, leading to unauthorized access to sensitive administrative functionality.

Rclone before v1.75.2 contains a credential exposure vulnerability in the b2 backend that leaks the live account Authorization token and SSE-C keys on HTTP redirects from --b2-download-url hosts. Attackers can observe a same-host HTTPS-to-HTTP downgrade redirect to capture the cleartext B2 token, or receive cross-host redirects disclosing SSE-C customer encryption keys.

Rclone before 1.75.2 contains a path traversal vulnerability in the local backend's translateLink function, which trims the .rclonelink suffix from a path after the containment check, so a name can resolve outside the destination root. Attackers can plant a directory named ...rclonelink in a source tree synced with --links and --metadata to change ownership, timestamps, and xattrs of the destination's parent directory.

Rclone from 1.52.0 before 1.75.2 contains a cross-site request forgery vulnerability in the pCloud backend's localhost OAuth callback, which disables the state check and trusts the hostname parameter. Malicious web pages can send a stateless request to port 53682 during authorization, planting attacker tokens and API hosts so later transfers reach the attacker.

Rclone from 1.64.0 before 1.75.2 contains an authentication bypass vulnerability in serve webdav that lets unauthenticated attackers skip authentication by sending OPTIONS requests. Attackers can probe arbitrary paths and compare Allow header values to determine whether files or collections exist, enabling namespace enumeration.

rclone from 1.37 before 1.74.2 contains a server-side request forgery vulnerability that allows unauthenticated attackers to redirect http and netstorage backend requests by supplying a double-slash root on an existing named remote via --rc-serve. Attackers can make HEAD/GET requests to attacker-chosen hosts to read responses, capture configured custom headers, or obtain valid NetStorage request signatures.

Rclone before 1.75.2 contains a path traversal vulnerability in serve webdav that allows unauthenticated attackers to write above the served root by sending an unvalidated '..' path component. Attackers can send MKCOL /.. to plant a VFS node, then PUT, MOVE, COPY, or MKCOL to create, overwrite, or delete files belonging to other tenants.

rclone from v1.56.0 before v1.75.2 contains an information disclosure vulnerability in the WebDAV backend that forwards operator-configured custom credential headers to different hosts on HTTP 3xx redirects. Attackers who control or influence a cross-host redirect can capture headers such as X-Auth-Token set via --webdav-headers and replay them against the original WebDAV service.

rclone from 1.55.0 before 1.75.2 contains a signature verification bypass in stable selfupdate that trusts checksums from unsigned bytes preceding the PGP-clearsigned SHA256SUMS block. Attackers controlling the release distribution path can prepend an unsigned checksum line matching a malicious archive, causing selfupdate to install an attacker-controlled rclone executable.

rclone serve s3 versions 1.75.0 before 1.75.2 contain an integer overflow vulnerability in multipart reorder-memory accounting that bypasses the configured buffer limit. Attackers can open two concurrent current-part PUT requests declaring huge lengths to wrap the signed int64 counter and retain out-of-order parts in memory, exhausting the host.

Rclone from v1.68.0 before v1.75.2 contains an authorization bypass vulnerability in serve s3 --auth-proxy that allows authenticated tenants to manipulate other tenants' multipart uploads by referencing their upload IDs. Attackers who learn a victim's bucket, object, and upload ID can inject parts, complete, or abort in-flight uploads and view upload and object metadata across tenants.

rclone versions 1.56.0 through 1.75.0 contain a path traversal vulnerability in the `rclone serve docker` volume plugin. newVolume() in cmd/serve/docker/volume.go computes a volume's mountpoint as filepath.Join(drv.root, name) from the attacker-supplied `name` field of a Docker VolumeDriver.Create request without verifying that the result stays within drv.root (default /var/lib/docker-volumes/rclone), and checkMountpoint() then creates that directory with file.MkdirAll before mounting. A volume name containing enough `..` components (e.g. "../../../../../../etc") therefore resolves outside the base directory, allowing anyone able to submit a VolumeDriver.Create request to the plugin socket to make the privileged rclone plugin process create a directory and mount a remote filesystem at an arbitrary host path. Volume.restoreState() had the same missing validation when reloading persisted volume state. Fixed in 1.75.1.

rclone before 1.75.1 fails to confine names from server and third-party listing responses to the listed directory, allowing path traversal sequences in object names. Attackers can craft special names containing forward slashes and parent directory references to potentially write outside the destination root, though downstream protections in the local backend currently block actual file escape.

Prior to rclone 1.75.1, the core does not reject parent-directory segments in source Object.Remote() values before fs/list, fs/walk, fs/sync, and fs/operations pass them to destination backends. A flat-keyspace source object store can contain a raw ".." key segment, and affected destinations use path.Join(root, remote) before EncodeDot can neutralize the segment, allowing a copy or upload to escape the configured root. This issue is fixed in version 1.75.1.

rclone from 1.75.0 until 1.75.1, in the serve S3 streamed multipart path, passes attacker-controlled contentLength to multipart.NewRW().Reserve before reading request-body bytes. A network client can retain or multiply these reservations without sending the declared body, exhausting process or host memory or permanently blocking request handlers. This is fixed in 1.75.1.

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.64.0 until 1.75.1, the FTP auth-proxy driver in cmd/serve/ftp/ftp.go stores one obscured password per username in the server-wide userPass map[string]string instead of binding the credential or VFS to the authenticated session. If two accepted credentials use the same username but resolve to different proxy backends, a later CheckPasswd login overwrites userPass[user], and subsequent getVFS operations on the first session are reauthorized with the later password. The first session can then read, create, overwrite, rename, or delete objects using the second credential’s backend authority. Exploitation requires the later same-username login to occur while the first session remains open. This issue is fixed in version 1.75.1.

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.1, when backend/local runs with --links, a source .rclonelink object can plant a symlink in the destination and later directory metadata is applied through that path. MkdirMetadata, writeMetadataToFile, and setTimes operate when Directory.translatedLink=false, so os.Chown, os.Chmod, os.Chtimes, and birth-time handling can bypass os.Root confinement and follow the symlink. An attacker controlling source contents can therefore apply selected ownership, permissions, modification times, or birth times to a file or directory outside the destination, with --metadata required for chmod and chown while modification time is applied by the normal directory workflow. This issue is fixed in version 1.75.1.

rclone is a command-line program to sync files and directories to and from different cloud storage providers. Prior to 1.75.1, backend/local with --links or links=true exposes symlink targets as .rclonelink objects, and fs.RangeOption.Decode can pass an unchecked positive Range start through Object.Open and openTranslatedLink. The function slices the target string as linkdst[offset:], so a Range start larger than the target length causes a deterministic slice-bounds panic when lib/http/serve exposes the object through HTTP or WebDAV. Go net/http normally recovers the panic per connection, causing request-level denial of service rather than terminating the entire process. This issue is fixed in version 1.75.1.

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.72.0 until 1.75.1, the archive ZIP backend method (*Fs).readZip in backend/archive/zip/zip.go accepts archive/zip.File.Name values from an untrusted central directory and exposes cleaned entry names without ensuring that they remain inside the archive namespace. Entries such as ../../etc/cron.d/evil can survive path.Clean and become Object.Remote() values that fs/sync and fs/operations use as destination-relative paths, allowing rclone copy or sync to write outside the selected destination on backends that do not independently confine the path. The non-empty root check also used strings.HasPrefix without a path boundary, so root foo could incorrectly include sibling foobar entries. This issue is fixed in version 1.75.1.

rclone is a command-line program to sync files and directories to and from different cloud storage providers. From 1.49.0 until 1.75.1, the HTTP backend attaches headers configured through --http-headers or headers= to requests in backend/http/http.go, while its fshttp.NewClient client follows redirects without a backend-specific http.Client.CheckRedirect policy. A configured remote that redirects to another host can therefore cause custom secrets such as X-Api-Key to be resent to that untrusted destination, and a same-host HTTPS-to-HTTP redirect can expose Authorization or Cookie headers in cleartext. Listing, stat, download, mount, and serve operations can trigger the leak during normal use. This issue is fixed in version 1.75.1.

rclone before 1.74.4 fails to mask special permission bits when applying source-supplied mode metadata in the local backend, allowing attackers to set setuid/setgid bits on attacker-controlled files. When copying with metadata preservation from an untrusted remote, attackers can plant a setuid binary that escalates privileges to root if rclone runs as root.

rclone before 1.74.4 fails to strip the X-Amz-Security-Token header when an S3 redirect changes scheme from HTTPS to HTTP on the same host. Attackers can intercept plaintext HTTP traffic to capture AWS STS session tokens sent in request headers.

rclone serve s3 before version 1.74.4 contains a path traversal vulnerability that allows attackers to read and overwrite root-level files by using dot-dot segments in S3 object keys. Attackers can send requests with object keys like '../root-secret.txt' to escape the bucket namespace and access files in the serve root directory.

rclone before v1.75.0 fails to sanitize IBM IAM bearer tokens and SSE-C encryption keys during S3 redirect callbacks, allowing credentials to be preserved across scheme or host changes. Attackers observing network traffic from a trusted endpoint can capture reusable IBM IAM tokens on same-host HTTPS-to-HTTP downgrades or SSE-C keys on cross-origin redirects to access protected S3 objects.

rclone versions before v1.75.0 fail to reject transport downgrades in redirect handling, allowing Basic authorization and Cookie headers to be replayed over plaintext HTTP after same-host HTTPS-to-HTTP redirects. An on-path attacker observing the plaintext hop can capture and reuse credentials to perform WebDAV operations with the compromised account's permissions.

rclone before v1.75.0 contains a denial of service vulnerability in the WebDAV TUS creation handler that dereferences a nil response before checking for transport errors. A malicious or compromised configured endpoint can reset connections during TUS uploads to trigger a panic that terminates unrecovered goroutines and halts unrelated work in long-lived processes.

rclone before v1.75.0 includes full Go stack traces in RC API error responses when panics occur. Attackers can trigger panics to leak internal file paths, module versions, goroutine states, and memory addresses.

rclone before version 1.75.0 mounts the pprof debug handler as its own router route, bypassing the fail-closed authentication rule in the main handler. Attackers can access the /debug/pprof/cmdline endpoint unauthenticated to retrieve the full process argv including backend credentials.

rclone versions >= v1.72.0 and <= v1.74.4 (fixed in v1.75.0) contain multiple denial-of-service vulnerabilities in the archive backend's SquashFS parser, which relies on the github.com/diskfs/go-diskfs dependency. The parser fails to validate attacker-controlled superblock and metadata values before use. An attacker who can place or modify a SquashFS image in storage exposed through an rclone :archive: remote can craft a malicious image that triggers an integer division-by-zero panic (zero block size), an out-of-bounds slice panic (out-of-range inode metadata offset), or a non-progress CPU loop (truncated metadata stream). Variants 1 and 2 terminate the rclone process and, via 'rclone serve sftp', can crash the entire SFTP server; variant 3 causes sustained CPU consumption. Parsing is lazy, so a victim or remote client must address or descend into the malicious archive object to trigger it.

rclone before version 1.75.0 has a vulnerability in the local backend that allows an attacker-controlled source object to create or overwrite files outside the configured destination directory. This occurs when the local destination uses certain filename encodings that can decode a '..' component into an actual parent directory.

rclone, a command-line program for syncing files with cloud storage, has a vulnerability where SFTP paths are interpolated into PowerShell commands, allowing an attacker-controlled filename to execute arbitrary PowerShell statements as the victim SSH account. Affects versions prior to 1.75.0; fixed in 1.75.0.

rclone before version 1.75.0 has a vulnerability in the FTP backend that allows injection of an independent authenticated FTP command when the victim copies or syncs to a more-privileged FTP destination. This occurs when a filename contains CR/LF characters that are not rejected by the FTP library.

rclone before version 1.75.0 has a vulnerability in the HTTP CONNECT helper that allows a malicious or compromised proxy to cause excessive memory consumption by sending oversized headers, potentially crashing the rclone process. The vulnerability affects FTP and SFTP proxy connections.

rclone serve restic fails to properly reject URL paths beginning with ../, allowing an attacker with REST endpoint access to read, create, overwrite, or delete objects outside the configured directory. Affects versions from 1.40.0 to 1.75.0; fixed in 1.75.0.

In Rclone before version 1.74.4, a vulnerability exists in the `rclone serve restic --private-repos` component. The authorization mechanism uses the routed user path segment while building the backend object key from the raw uncleaned URL path, allowing an authenticated user to include `..` in a request (e.g., `//..//config`) and read, overwrite, or delete another user's private repository on backends that clean path components.

Rclone before version 1.74.4 has a vulnerability in the archive extract function that allows extracted files to be written outside the user-selected destination directory when extracting a crafted archive containing parent path components (e.g., ../). This allows creation or overwrite of sibling objects in the same bucket or path scope.

In Rclone prior to version 1.74.4, when using the -l/--links flag, symlinks are serialized as .rclonelink text objects and recreated on a local destination without validating the target. This allows an attacker-controlled remote to plant an escaping symlink and cause a subsequent object write to land outside the destination with attacker-chosen contents.