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Attention PGP Users: New Vulnerabilities Require You To Take Action Now (eff.org)
A group of European security researchers have released a warning about a set of vulnerabilities affecting users of PGP and S/MIME. From a report: EFF has been in communication with the research team, and can confirm that these vulnerabilities pose an immediate risk to those using these tools for email communication, including the potential exposure of the contents of past messages. The full details will be published in a paper on Tuesday at 07:00 AM UTC (3:00 AM Eastern, midnight Pacific).
In order to reduce the short-term risk, we and the researchers have agreed to warn the wider PGP user community in advance of its full publication. Our advice, which mirrors that of the researchers, is to immediately disable and/or uninstall tools that automatically decrypt PGP-encrypted email. Until the flaws described in the paper are more widely understood and fixed, users should arrange for the use of alternative end-to-end secure channels, such as Signal, and temporarily stop sending and especially reading PGP-encrypted email. Further reading: People Are Freaking Out That PGP Is 'Broken' -- But You Shouldn't Be Using It Anyway (Motherboard).
In order to reduce the short-term risk, we and the researchers have agreed to warn the wider PGP user community in advance of its full publication. Our advice, which mirrors that of the researchers, is to immediately disable and/or uninstall tools that automatically decrypt PGP-encrypted email. Until the flaws described in the paper are more widely understood and fixed, users should arrange for the use of alternative end-to-end secure channels, such as Signal, and temporarily stop sending and especially reading PGP-encrypted email. Further reading: People Are Freaking Out That PGP Is 'Broken' -- But You Shouldn't Be Using It Anyway (Motherboard).
The problem is the clients decrypt, then process any external requests for content. So if you can re-send an encrypted email with an external content request added to it, the client will happily decrypt then send the content request with your precious decrypted content. If you globally disable fetching any external content you don't have to worry. The encryption protocols all work fine, it is the behavior of the clients after the decryption that is the problem. So S/MIME would be affected too, or potentially any other encryption tool. Refusing to load any external content under any circumstances is good advice anyway.
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Isn't this supposed to be a peer reviewed protocol that was guaranteed to be secure? How long has this program existed? Holy shit.
The problem is in how email program plugins handle the mail after it's been decrypted, not in the underlying PGP/SMIME code.
Yes, indeed, some advice there. Because there is some potential for bad actors to possibly decrypt some of the PGP encrypted messages, if said messages include HTML with links to 3rd party sites (which your email client must display automatically), you need to **completely disable** email encryption. Then all of your email becomes clear text and, fully readable by anyone without effort, and thus you are completely safe from that vulnerability. SMH.
That wonderful advice is brought to you by researchers in no way sponsored by NSA or any other 3 letter agency.
For those worried - make sure your email client does not automatically display any embedded HTML links (or, better yet, just turn off HTML formatted email). I believe this is the default for Enigmail encrypted email anyway. Use plaintext, and you are as safe as cryptography allows. (I believe Enigmail authors posted a message to that effect).
The key word was *automatically* – although it is not always clear in the press what you are supposed to do. So confusion will abound. No surprise there.
In the end, you can still use PGP, but you have to do more work to be safe. I think, if you understand how to use PGP to begin with, you can probably help yourself for now. If not, well ....
In your terms: keep your locks. But disable the remote locking feature (take the battery out) and don't use your app to lock your house - use your good old key you stored away in a box a long time ago. Yes, you will have to do actual work. And yes, someone can still break in - probably through the window. Or by kicking in the door ...
Do your own thing. And overdo it!
From https://lists.gnupg.org/piperm... :
> 1. This paper is misnamed.
Indeed
> 2. This attack targets buggy email clients.
Exactly
> 3. The authors made a list of buggy email clients.
Well said.
The MUA should not allow *any* utilization of HTTP when rendering a HTML E-mail. Any form of doing that is a serious mistake. Not only because of what is reported here, but also because that way *that* use of HTTP will allow spammers to identify when you open the E-mail. They use that to know if your E-mail adress is still alive.
Serious MUAs don't do this without user consent. Most HTML components even have a explicit offline mode exactly for that reason. Meaning that they won't automatically go online and fetch things like the src url of an IMG.
Any MUA that does this without user consent is completely and utterly wrong. Especially in a security sensitive context. This is something most MUA developers know about and if not, should know.
PGP is broken now? It's only had fairly infrequent and minor issues over time. If this is broken now, then it's the final sign that anyone who thinks computers can be secured is wrong. If you want something secure, write it down in a notebook. It'll be about 100x more secure than putting it on a computer simply by not being networked. Even if someone steals and reads your notebook it's better than someone having it on their phone (or PGP, now I guess) for the ENTIRE WORLD to come along and steal. Computers are great for games, everything else is debatable.
PGP is not broken. The way a few bad email clients are using it is broken. If you are not using Thunderbird you are safe with PGP. While S/MIME is comprised in every email client except modern Outlook, KMail, and mutt.