- tor-relays - lists.torproject.org

Advisory: Unauthenticated remote trigger of Hetzner's "Netscan" detection
by invisibleprefixes＠mailbox.org 01 Mar '26

01 Mar '26

CVSS v4.0 Score: 6 / Medium CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N Hetzner aims to detect portscans from within their network to targets outside their network, especially to destinations not visible via BGP. When their outbound scan detection triggers on a given customer IP address the customer gets an email: "Netscan detected from host ..." If the customer does not react in time, the customer's source IP is blocked from any further communication until the customer responds to the report. According to Hetzner the blocking is enforced after "manual verification" only. Vulnerability Description ========================= An unauthenticated remote attacker, who is able to trigger outbound packets from a given Hetzner customer source IP, can trigger the described portscan detection and block a Hetzner customer's Internet access if the customer does not respond to Hetzner in time. There are many services that allow the provocation of outbound packets by design, a few popular examples: * SMTP: various outbound checks performed for incoming emails (SPF, DKIM, DMARC, ...). The attacker can influence the target of outbound destinations by sending emails from domains under their control. * DNS: Recursive resolver are usually not directly exposed to the public but other servers (SMTP, Webserver, ...) might use resolvers located within the Hetzner network. * Web Applikations can have features that allow users to trigger outbound connections to arbitrary destinations. Examples: * Link previews generated server side (for example on a fediverse server) * Server-Side RSS Readers * Server-Side Request Forgery (SSRF) weaknesses * tor relays It is NOT possible to exploit this without a service on the target system by using source IP spoofing with source IPs from prefixes not announced via BGP. Impact An unauthenticated remote attacker can - in the worst-case - block a Hetzner customer's server Internet access and take all services offline (denial of service) until the block is removed. If a host has multiple source IP addresses only the actually used source IP address is blocked. The integrity and confidentiality of the system is NOT affected. Timeline ======== * 2026-01-04: Advisory is sent to security(a)hetzner.com - including the intended release date of the advisory (2026-02-05). * 2026-01-13: Asked Hetzner for an update via email * 2026-01-27: Sent Advisory to bsi.bund.de * 2026-01-28: Hetzner answered: According to Hetzner it is a customer responsibility to deal with this. * 2026-01-28: We asked Hetzner to clarify how their customers should mitigate this risk if it is their responsibility (no answer). * 2026-02-06: Reply from Hetzner stating that this can not be exploited via source IP spoofing - which we did not claim. * 2026-02-06: We offer a call to clarify the issue * 2026-02-06: Hetzner reply: they will get back to us on 2026-02-10 * 2026-02-06: Advisory publication is postponed due to ongoing emails. * 2026-02-10: Clarify that no source IP address spoofing is involved. * 2026-02-12: Asked Hetzner if they have any further questions and if they have any feedback on the advisory release date (no answer). * 2026-03-01: Advisory is released. Credits ======== We did not discover this and we do not take any credits for the discovery of this issue. This issue got discovered because the Netscan detection also got triggered during BGP outages where some IP prefixes were no longer visible via BGP. Some Hetzner customers were affected by these BGP outages causing Netscan detections.

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No. of connections according to nyx
by tor＠busybear.se 01 Mar '26

01 Mar '26

Hello! I would like to know what is considered a normal amount of connections and what affects that? My exit 7BE9E2EF2BB41BB662D9A3CD68289B9E3DBF8A08 WYSWYG hovers around 4500 inbound, 4200 outbound and sometimes a few directory connections, according to nyx. Output in Mb varies, but increases with the normal lifespan of relays. Is this important, will this increase over time, thus generate more traffic, or does it matter? From what I remember, this have been roughly the same during the lifetime of this relay, no matter what connection speed (5Mb - 1Gb) or which machine I've been running. No restrictions in torrc, as far as I know; Nickname WYSWYG Contactinfo <tor AT busybear DOT se> ExitRelay 1 IPv6Exit 1 Log notice file /home/*/torlog SafeLogging 1 ProtocolWarnings 1 RunAsDaemon 1 ControlPort 9051 CookieAuthentication 1 CookieAuthFileGroupReadable 1 CookieAuthFile /home/*/Downloads/control_auth_cookie ConnDirectionStatistics 1 ExtraInfoStatistics 1 DirPort 65534 ORPort 65535 NumCPUs 6 Any comments or suggestions are welcome! Cheers! //Bamse

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Hibernate vs 10 Mbps throttle when bandwidth cap exceeded
by forest-relay-contact＠cryptolab.net 01 Mar '26

01 Mar '26

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello. Many server providers have a monthly bandwidth limit. It's easy enough to deal with that by using the AccountingMax option so that Tor will hibernate when it reaches the bandwidth cap to avoid service suspension. I run a relay on a provider that, rather than suspending the service, simply throttles the bandwidth to 10 Mbps until the next month when the 8 TB/month traffic cap is reset. I run through that traffic in just half a month, so the relay is only operational 50% of the time. But 10 Mbps is not nothing. What should I do here? I can think of a few options: 1. Set AccountingMax and let the relay hibernate like normal, ensuring that, whenever it is on, it can achieve maximum performance. The "free" 10 Mbps bandwidth can then be used for other things, such as I2P which does not have a ramp-up period. 2. Keep the relay running, relaying up to 1.5 TB/month extra for free, but with the caveat that the relay suddenly becomes overloaded each time it reaches the 8 TB mark until the consensus weight falls. 3. Shortly before the bandwidth cap is exceeded, automatically adjust the torrc to include "MaxAdvertisedBandwidth 10 Mbits", and remove it when the bandwidth cap resets. What is a reasonable thing to do here? Regards, forest -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQQtr8ZXhq/o01Qf/pow+TRLM+X4xgUCaY/3wQAKCRAw+TRLM+X4 xtgQAQC2HWAGe7tcmuOGu2v/473IQC9lWHL03lUUpuJPSpGZpwD+LItXaqzV4vPy phr/rC4LNDZ1AY8m2ZuTzd4MwsVpsgI= =c+pq -----END PGP SIGNATURE-----

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big german provider "Deutsche Telekom" has started blocking access to their SIP servers
by iji＠gmx.net 28 Feb '26

28 Feb '26

Hi a big German provider "Deutsche Telekom" has started blocking access (at TCP layer) to their SIP servers in February 2026. That means running a middle tor on this provider line results in a non-functional provider SIP service. You have to choose between running a middle tor or a working provider SIP service.

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Happy Families migration status dashboard
by Tor at 1AEO 24 Feb '26

24 Feb '26

To help answer “what still needs to happen before the network can rely on Happy Families (and eventually stop depending on MyFamily)?”, we put together a small public dashboard that tracks the main rollout gates: https://metrics.1aeo.com/network-health.html#happy-families High-level flow: 1) Voting directory authorities upgrade (v0.4.9.x+) DAs need to be on v0.4.9.x+ so the network can move forward with the newer directory protocol pieces. 2) Consensus method moves to 35 Once a >2/3 voting DA majority supports method 35 (7/9), the consensus can adopt it. 3) Relays publish Happy Families material Relay families configure FamilyId so relays publish family-cert, which lets directory documents/micro descriptors carry the happy families identifier information. 4) Clients upgrade and use it As Tor clients (Tor Browser, tor, etc.) widely consume happy families identifiers, then deprecating MyFamily becomes possible. The dashboard shows live counts for DA readiness (v0.4.9.x+ and method-35 support), current consensus method, relay publication (family-cert), and a few “how much of the network is ready” slices (guards/exits/CW/bandwidth). References: - Relay operator guide (FamilyId / Happy Families setup): https://community.torproject.org/relay/setup/post-install/family-ids/ - Proposal 321: https://spec.torproject.org/proposals/321-happy-families.html Feedback welcome—especially if there are other readiness signals you’d like to track, or if you spot anything that looks off for your relays. On Tuesday, February 3rd, 2026 at 5:00 AM, Alexander Hansen Færøy via tor-relays <tor-relays(a)lists.torproject.org> wrote: > On 02/02/2026 22.36, tor_appliedprivacy.net via tor-relays wrote: > > Today we enabled the happy family setup across all our relays. > > > > Since all our relays run in a single /24 we also removed MyFamily at the > > same time. This should help reduce the overhead introduced by MyFamily. > > This is not what any of us on the Network Team are recommending right now, but > if others think this is a good idea despite that: please ensure that your IPv6 > addresses, at the very least, are also within the same /32 in addition to the > /16 requirement for IPv4. I am almost certain that is always the case, but > please just be sure before you proceed. > > We are very interested in hearing feedback on the 0.4.9.4-rc release candidate > and in resolving any issues before we stabilize 0.4.9. Maybe the above approach > will reveal some issues :-) > > Cheers, > Alex > > -- > Alexander Hansen Færøy > _______________________________________________ > tor-relays mailing list -- tor-relays(a)lists.torproject.org > To unsubscribe send an email to tor-relays-leave(a)lists.torproject.org >

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Question about Tor relay guard/middle probability fluctuations
by Tor-relay 23 Feb '26

23 Feb '26

Hi everyone, I have a question regarding my Tor relay’s lifecycle. Since the beginning, I have noticed that the guard and middle probabilities fluctuate significantly. I have not observed this behavior when comparing with other operators’ relays. After some time, the relay receives the Guard flag and the middle probability decreases, later it loses the Guard flag and the middle probability increases again. I waited for a long time to see whether this would stabilize, but the behavior has remained unchanged. I would like to ask what the possible reasons for this could be, and whether it might be related to my configuration. Relay fingerprint: 8E6E3B11C9AD2E9E3B3FC53A4E43D1AE3BEBE444 Tor metrics link: https://metrics.torproject.org/rs.html#details/8E6E3B11C9AD2E9E3B3FC53A4E43… Thank you in advance. P.S. If you check the relay statistics, please ignore the low consensus weight and probabilities during the last month, that was caused by my own mistake.

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the case for relay state persistency
by Gilberto 23 Feb '26

23 Feb '26

Hello everyone, In our diskless infrastructure [0][1], we store all configurations generated by the node inside the TPM's memory. These memories are very limited (1-9k), but more than sufficient for saving the long-term keys of the relays. However, we have a problem: when rebooting the machines, we lose the state file and, with it, the bandwidth measurements of the various relays. This is quite annoying because upon reboot, our relays all start up announcing 0 B/s, and it takes them days to regain their bandwidth. Unfortunately, these files are too large to be stored in the TPM. We would like to be able to generate the BWHistory configurations based on some arbitrary values that we write into the node configurations, and then let the node handle redoing the measurements upon reboot. However, among all the configurations, it's not clear to us which ones are important for our needs and which others we can leave empty. In general, we would like to open a discussion, in view of Arti, about the organization of the datadir. Currently, it's not very clear which files are important for runtime, which are for persistence, etc. From our point of view, it would be quite useful to be able to group persistent data into just a few files, for example, one for all keys and one for states/configurations. Thank you, g [0]: https://osservatorionessuno.org/blog/2025/05/patela-a-basement-full-of-amne… [1]: https://osservatorionessuno.org/blog/2025/12/patela-v2-from-certificates-to…

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Re: Issues with My Tor Relay
by stay.hydrated834＠passmail.net 22 Feb '26

22 Feb '26

Hi everyone, Thank you for the reply and the information you provided. While preparing my response about the blocked traffic, I wanted to clarify the NAT and WAN rules in the screenshots and replace the aliases with the actual IP addresses. During that process I discovered that I (the numb nut of an administrator) forgot to fill in the NAT alias, so there was never an active NAT rule only the WAN rule was present. Because both the NAT and WAN rules are now active, the Tor relay is functioning correctly: no traffic to port 9001 is being blocked, and outbound traffic is unrestricted. I wonder why some connections were allowed by the WAN rule while others were denied and are now only allowed due to the NAT rule. Bandwidth: Average throughput: ~60 Mbps (occasionally up to 140 Mbps) Recent spikes: short bursts up to 420 Mbps training i guess? Due to frequent firewall restarts while I’m re‑configuring my network. I expect the traffic to stabilize as the network settles and after the training finished, and I’m happy if the relay can make use of any unused capacity. 1000Mbps would be the Maximum so there is alot of room to grow. :D Unexpected traffic bursts Every few hours I see dozens of Tor nodes connecting to my relay for 2–5 minutes, resulting in 1,000–7,500 connections dropping. These bursts don’t line up with the bandwidth spikes as far as i seen. My CPU usage, which is usually around 1 %, can rise to about 1.2 % during those periods. Im glad i already thought its static. :D I don’t think this is an attack—nothing I’ve seen, even a smart bulb, generates comparable traffic. I’m wondering if I still have a misconfiguration somewhere. Regarding Snowflakes Is it possible to Route all of my phones (apps) traffic still through WireGuard back to home while allowing Orbot to use the mobile network to open a Snowflake relay (my IP changes every 24 hours after a phone reboot). I have an unlimited 25Mbit not fast but steady. Im on GrapheneOS Screenshots I’ve attached screenshots that highlight exactly what is being blocked, so you can see the traffic patterns I described. Thanks again to everyone who runs relays; your experience helped me finally get mine working. <3 Stay hydrated! Cheers

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Scheduled migration: Nothing to hide infrastructure (23-02-2026)
by Nothing to hide 20 Feb '26

20 Feb '26

Hi everyone, This is a heads-up that a significant portion of the Nothing to hide infrastructure will be undergoing a major upgrade and migration on Monday 23 February 2026. We are replacing older servers and networking equipment with modern high-performance hardware and moving to a new data center. What to expect: * While we aim to limit downtime to a few minutes, extended outages are possible depending on how the migration proceeds. * In the days following the migration, many of our existing relays will be assigned new IP addresses and/or roles. * Once we consider the new network and infrastructure stable, we will be adding more relays to the network. This move also provides much-needed headroom for auxiliary services we plan to offer Tor operators, such as DoT, DoH, DoQ, and NTS. We'll share more details on these in the near future. Best regards, Nothing to hide

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Programmatically determine if a relay is hibernating
by forest-relay-contact＠cryptolab.net 18 Feb '26

18 Feb '26

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 Hello. What is the authoritative way to determine if a relay is hibernating? I would have thought that using the control socket would be best, but Tor seems to unlink it when it enters hibernation, so Stem does not work. There's a possible heuristic by checking if /run/tor/tor.pid exists when /run/tor/control does not, but that's fragile because it assumes that the control socket is even enabled. Parsing the logs is doable, but also quite fragile. And I could certainly parse /var/lib/tor/state, but its format is surely subject to change at any time. How do I correctly determine whether a Tor process is in hibernation? Regards, forest -----BEGIN PGP SIGNATURE----- iHUEARYKAB0WIQQtr8ZXhq/o01Qf/pow+TRLM+X4xgUCaZERAgAKCRAw+TRLM+X4 xshIAQCjNVgq0vBzT+MJhbn8Vetj3UObU8DinVvp3gtj9DeLKgD/aKy7N3nvCUSu zFSSFZTCR0MFxQh9TxjmYO/tKRrPoAE= =gAnQ -----END PGP SIGNATURE-----

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