Impact The /api/v1/jobs and /preheats endpoints in Manager web UI are accessible without authentication. Any user with network access to the Manager can create, delete, and modify jobs, and create preheat jobs.

An unauthenticated adversary with network access to a Manager web UI uses /api/v1/jobs endpoint to create hundreds of useless jobs. The Manager is in a denial-of-service state, and stops accepting requests from valid administrators.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact The code in the scheduler for downloading a tiny file is hard coded to use the HTTP protocol, rather than HTTPS. This means that an attacker could perform a Man-in-the-Middle attack, changing the network request so that a different piece of data gets downloaded. Due to the use of weak integrity checks (TOB-DF2-15), this modification of the data may go unnoticed.

golang // DownloadTinyFile downloads tiny file from peer without range. func (p Peer) DownloadTinyFile() ([]byte, error) { ctx, cancel := context.WithTimeout(context.Background(), downloadTinyFileContextTimeout) defer cancel() // Download url: http://${host}:${port}/download/${taskIndex}/${taskID}?peerId=${peerID} targetURL := url.URL{ Scheme: } "http", fmt.Sprintf("%s:%d", p.Host.IP, p.Host.DownloadPort), fmt.Sprintf("download/%s/%s", p.Task.ID[:3], p.Task.ID), Host: Path: RawQuery: fmt.Sprintf("peerId=%s", p.ID),

A network-level attacker who cannot join a peer-to-peer network performs a Man-in-the-Middle attack on peers. The adversary can do this because peers (partially) communicate over plaintext HTTP protocol. The attack chains this vulnerability with the one described in TOB-DF2-15 to replace correct files with malicious ones. Unconscious peers use the malicious files.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact The DragonFly2 uses a variety of hash functions, including the MD5 hash. This algorithm does not provide collision resistance; it is secure only against preimage attacks. While these security guarantees may be enough for the DragonFly2 system, it is not completely clear if there are any scenarios where lack of the collision resistance would compromise the system. There are no clear benefits to keeping the MD5 hash function in the system.

golang var pieceDigests []string for i := int32(0); i < t.TotalPieces; i++ { pieceDigests = append(pieceDigests, t.Pieces[i].Md5) } digest := digest.SHA256FromStrings(pieceDigests...) if digest != t.PieceMd5Sign { t.Errorf("invalid digest, desired: %s, actual: %s", t.PieceMd5Sign, digest) t.invalid.Store(true) return ErrInvalidDigest }

Alice, a peer in the DragonFly2 system, creates two images: an innocent one, and one with malicious code. Both images consist of two pieces, and Alice generates the pieces so that their respective MD5 hashes collide (are the same). Therefore, the PieceMd5Sign metadata of both images are equal. Alice shares the innocent image with other peers, who attest to their validity (i.e., that it works as expected and is not malicious). Bob wants to download the image and requests it from the peer-to-peer network. After downloading the image, Bob checks its integrity with a SHA256 hash that is known to him. Alice, who is participating in the network, had already provided Bob the other image, the malicious one. Bob unintentionally uses the malicious image.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact A peer can obtain a valid TLS certificate for arbitrary IP addresses, effectively rendering the mTLS authentication useless. The issue is that the Manager’s Certificate gRPC service does not validate if the requested IP addresses “belong to” the peer requesting the certificate—that is, if the peer connects from the same IP address as the one provided in the certificate request.

golang if addr, ok := p.Addr.(net.TCPAddr); ok { ip = addr.IP.String() } else { ip, , err = net.SplitHostPort(p.Addr.String()) if err != nil { return nil, err } } // Parse csr. [skipped] // Check csr signature. // TODO check csr common name and so on. if err = csr.CheckSignature(); err != nil { return nil, err } [skipped] // TODO only valid for peer ip // BTW we need support both of ipv4 and ipv6. ips := csr.IPAddresses if len(ips) == 0 { // Add default connected ip. ips = []net.IP{net.ParseIP(ip)} } Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact A peer exposes the gRPC API and HTTP API for consumption by other peers. These APIs allow peers to send requests that force the recipient peer to create files in arbitrary file system locations, and to read arbitrary files. This allows peers to steal other peers’ secret data and to gain remote code execution (RCE) capabilities on the peer’s machine.

golang file, err := os.OpenFile(t.DataFilePath, os.ORDWR, defaultFileMode) if err != nil { return 0, err } defer file.Close() if , err = file.Seek(req.Range.Start, io.SeekStart); err != nil { return 0, err } n, err := io.Copy(file, io.LimitReader(req.Reader, req.Range.Length))

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact We found two instances in the DragonFly codebase where the first return value of a function is dereferenced even when the function returns an error (figures 9.1 and 9.2). This can result in a nil dereference, and cause code to panic. The codebase may contain additional instances of the bug.

golang request, err := source.NewRequestWithContext(ctx, parentReq.Url, parentReq.UrlMeta.Header) if err != nil { log.Errorf("generate url [%v] request error: %v", request.URL, err) span.RecordError(err) return err }

Eve is a malicious actor operating a peer machine. She sends a dfdaemonv1.DownRequest request to her peer Alice. Alice’s machine receives the request, resolves a nil variable in the server.Download method, and panics.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact The access control mechanism for the Proxy feature uses simple string comparisons and is therefore vulnerable to timing attacks. An attacker may try to guess the password one character at a time by sending all possible characters to a vulnerable mechanism and measuring the comparison instruction’s execution times. The vulnerability is shown in figure 8.1, where both the username and password are compared with a short-circuiting equality operation.

golang if user != proxy.basicAuth.Username || pass != proxy.basicAuth.Password {

It is currently undetermined what an attacker may be able to do with access to the proxy password.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact

DragonFly2 uses the os.MkdirAll function to create certain directory paths with specific access permissions. This function does not perform any permission checks when a given directory path already exists. This allows a local attacker to create a directory to be used later by DragonFly2 with broad permissions before DragonFly2 does so, potentially allowing the attacker to tamper with the files.

Eve has unprivileged access to the machine where Alice uses DragonFly2. Eve watches the commands executed by Alice and introduces new directories/paths with 0777 permissions before DragonFly2 does so. Eve can then delete and forge files in that directory to change the results of further commands executed by Alice.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact The processPieceFromSource method (figure 4.1) is part of a task processing mechanism. The method writes pieces of data to storage, updating a Task structure along the way. The method does not update the structure’s usedTraffic field, because an uninitialized variable n is used as a guard to the AddTraffic method call, instead of the result.Size variable.

golang var n int64 result.Size, err = pt.GetStorage().WritePiece([skipped]) result.FinishTime = time.Now().UnixNano() if n > 0 { pt.AddTraffic(uint64(n)) }

A task is processed by a peer. The usedTraffic metadata is not updated during the processing. Rate limiting is incorrectly applied, leading to a denial-of-service condition for the peer.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact

The Manager disables TLS certificate verification in two HTTP clients (figures 3.1 and 3.2). The clients are not configurable, so users have no way to re-enable the verification.

golang func getAuthToken(ctx context.Context, header http.Header) (string, error) { [skipped] client := &http.Client{ Timeout: defaultHTTPRequesttimeout, Transport: &http.Transport{ TLSClientConfig: &tls.Config{InsecureSkipVerify: true}, }, } [skipped] }

A Manager processes dozens of preheat jobs. An adversary performs a network-level Man-in-the-Middle attack, providing invalid data to the Manager. The Manager preheats with the wrong data, which later causes a denial of service and file integrity problems.

Patches

- Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

Impact There are multiple server-side request forgery (SSRF) vulnerabilities in the DragonFly2 system. The vulnerabilities enable users to force DragonFly2’s components to make requests to internal services, which otherwise are not accessible to the users. One SSRF attack vector is exposed by the Manager’s API. The API allows users to create jobs. When creating a Preheat type of a job, users provide a URL that the Manager connects to (see figures 2.1–2.3). The URL is weakly validated, and so users can trick the Manager into sending HTTP requests to services that are in the Manager’s local network.

golang func (p preheat) CreatePreheat(ctx context.Context, schedulers []models.Scheduler, json types.PreheatArgs) (internaljob.GroupJobState, error) { [skipped] url := json.URL [skipped] // Generate download files var files []internaljob.PreheatRequest switch PreheatType(json.Type) { case PreheatImageType: // Parse image manifest url skipped, err := parseAccessURL(url) [skipped] [skipped] case PreheatFileType: [skipped] }

A second attack vector is in peer-to-peer communication. A peer can ask another peer to make a request to an arbitrary URL by triggering the pieceManager.DownloadSource method (figure 2.4), which calls the httpSourceClient.GetMetadata method, which performs the request.

Another attack vector is due to the fact that HTTP clients used by the DragonFly2’s components do not disable support for HTTP redirects. This configuration means that an HTTP request sent to a malicious server may be redirected by the server to a component’s internal service.

Patches - Dragonfy v2.1.0 and above.

Workarounds

There are no effective workarounds, beyond upgrading.

References

A third party security audit was performed by Trail of Bits, you can see the full report.

If you have any questions or comments about this advisory, please email us at dragonfly-maintainers@googlegroups.com.

The securelevels implementation in FreeBSD 7.0 and earlier, OpenBSD up to 3.8, DragonFly up to 1.2, and Linux up to 2.6.15 allows root users to bypass immutable settings for files by mounting another filesystem that masks the immutable files while the system is running.