5 ms·

Can you revise that "9" number, because looking at it I feel like some of those are inappropriately filed against postfix. I find it hard to pin a "postfixadmi

Can you revise that "9" number, because looking at it I feel like some of those are inappropriately filed against postfix. I find it hard to pin a "postfixadmin" CVE on postfix, are we going to blame vmailmgr bugs on qmail? :-) The BSDDB one I'm on the fence about. "postfix_groups.pl" is marked as disputed. Another seems to be clearly a Debian package issue. CVE-2011-0411 is interesting because, IIRC, qmail had no SSL/TLS abilities, and the hacks you had to put into place to enable it were abominations and likely opened up issues of their own.

sigil 7y ago
Fine, let’s call it 7, since postfixadmin & the debian postinst script can’t be attributed to postfix proper. I’m not sure this qualitatively changes the argument. CVE-2011-1720 and CVE-2008-2936 are examples of postfix vulns no one has found, or reasonably expects to find, in djb code.
- pilif 7y ago
  > CVE-2011-1720 and CVE-2008-2936 are examples of postfix vulns no one has found, or reasonably expects to find, in djb code. CVE-2011-1720 is related to SMTP authentication which qmail doesn't support out-of-the box. So. Yes you're right: You don't find that vulnerability in qmail because qmail doesn't have that feature. Can you run an SMTP server without authentication these days? Not if you have users using you as a relay. So I guess you have to custom patch qmail and now you're back to not running djb code in the first place. CVE-2008-2936 I grant you. Though once we are at doing hardlinks to symlinks, we might hit other edge-cases too, some might even affect qmail in some way.
  - geocar 7y ago
    Road warriors with Thunderbird may need SMTP authentication, but most people do relaying with just IP authentication just fine.
    - pilif 7y ago
      Aside of the fact that I doubt your "most people" assertion here, it's beside the point that I was trying to make which is that a CVE affecting a feature of Postfix that qmail doesn't have to begin with is not a fair mark against postfix. Because if you disable a feature you don't use, you won't be affected by the vulnerability. If you use smtp authentication, you're not running djb's code and all advantages of djb's code are moot. If you don't use smtp authentication then that CVE is inconsequential and you can't count it as a black mark against Postfix with regards to the security of your specific setup.
      - geocar 7y ago
        > it's beside the point that I was trying to make which is that a CVE affecting a feature of Postfix that qmail doesn't have to begin with is not a fair mark against postfix. I disagree. It is a fair mark against postfix if (as I claim) most users really don't need it. Here's my reasoning to that point: I think most email end-users either use their ISPs mail settings (who know who they are and don't need authentication), or webmail (which doesn't use SMTP for relaying anyway), or outlook (which doesn't need SMTP at all). Fastmail is becoming more popular and it doesn't need SMTP either. The end-users who remain are either business users (who could use a VPN which is better than SMTP AUTH in every way), and nutters with vanity domains. If that's contended, and note I do believe there are probably end users who are actually still manually entering SMTP AUTH settings into email clients, but I would struggle to believe they're the majority and would need evidence. Meanwhile on the enterprise, pretty much every machine in every enterprise environment I've ever worked in has been set up for local relay. Again, if you think they're all using SMTP AUTH I'd need to see evidence. > If you use smtp authentication, you're not running djb's code and all advantages of djb's code are moot Do you actually believe that if you apt-get install postfix that you don't have any of the advantages of postfix's development processes? I'm not sure I can engage with that. It's like saying running linux invalidates "all advantages of djb's code" simply because you're (sometimes) not running his code (e.g. when you're in a syscall). Madness runs down that way. For what it's worth, most of the qmail smtpd patches I've seen to add SMTP AUTH (including the one I wrote nearly twenty years ago) are sensible, integrate well with the rest of qmail. You might not get djb's warrantee, but I can't believe you gain nothing by starting from a solid foundation.
  - sigil 7y ago
    > You don't find that vulnerability in qmail because qmail doesn't have that feature. But being selective about what features to add is itself a valid strategy for writing secure software — perhaps even the most effective one!
    - deleted 7y ago
      [deleted]
    - pilif 7y ago
      I agree. But if the software is lacking essential features so that everybody patches them back in it's a very ineffective strategy because anybody's home-grown patches are worse than properly maintained features. I can put a machine on the net with a closed port 25. That's the most minimal implementation of an MTA and it's entirely secure. Guaranteed. The thing is that qmail was severely lacking features back in the 90ies and it has received zero feature additions by its original author since then, so it's safe to assume that it's now lacking even more features to the point where anybody running qmail these days is nearly guaranteed to be running franken-qmail full of third-party patches which are surely less well maintained than proper Postfix. That was my point.

sigil 7y ago

Fine, let’s call it 7, since postfixadmin & the debian postinst script can’t be attributed to postfix proper. I’m not sure this qualitatively changes the argument. CVE-2011-1720 and CVE-2008-2936 are examples of postfix vulns no one has found, or reasonably expects to find, in djb code.

pilif 7y ago
> CVE-2011-1720 and CVE-2008-2936 are examples of postfix vulns no one has found, or reasonably expects to find, in djb code. CVE-2011-1720 is related to SMTP authentication which qmail doesn't support out-of-the box. So. Yes you're right: You don't find that vulnerability in qmail because qmail doesn't have that feature. Can you run an SMTP server without authentication these days? Not if you have users using you as a relay. So I guess you have to custom patch qmail and now you're back to not running djb code in the first place. CVE-2008-2936 I grant you. Though once we are at doing hardlinks to symlinks, we might hit other edge-cases too, some might even affect qmail in some way.
- geocar 7y ago
  Road warriors with Thunderbird may need SMTP authentication, but most people do relaying with just IP authentication just fine.
  - pilif 7y ago
    Aside of the fact that I doubt your "most people" assertion here, it's beside the point that I was trying to make which is that a CVE affecting a feature of Postfix that qmail doesn't have to begin with is not a fair mark against postfix. Because if you disable a feature you don't use, you won't be affected by the vulnerability. If you use smtp authentication, you're not running djb's code and all advantages of djb's code are moot. If you don't use smtp authentication then that CVE is inconsequential and you can't count it as a black mark against Postfix with regards to the security of your specific setup.
    - geocar 7y ago
      > it's beside the point that I was trying to make which is that a CVE affecting a feature of Postfix that qmail doesn't have to begin with is not a fair mark against postfix. I disagree. It is a fair mark against postfix if (as I claim) most users really don't need it. Here's my reasoning to that point: I think most email end-users either use their ISPs mail settings (who know who they are and don't need authentication), or webmail (which doesn't use SMTP for relaying anyway), or outlook (which doesn't need SMTP at all). Fastmail is becoming more popular and it doesn't need SMTP either. The end-users who remain are either business users (who could use a VPN which is better than SMTP AUTH in every way), and nutters with vanity domains. If that's contended, and note I do believe there are probably end users who are actually still manually entering SMTP AUTH settings into email clients, but I would struggle to believe they're the majority and would need evidence. Meanwhile on the enterprise, pretty much every machine in every enterprise environment I've ever worked in has been set up for local relay. Again, if you think they're all using SMTP AUTH I'd need to see evidence. > If you use smtp authentication, you're not running djb's code and all advantages of djb's code are moot Do you actually believe that if you apt-get install postfix that you don't have any of the advantages of postfix's development processes? I'm not sure I can engage with that. It's like saying running linux invalidates "all advantages of djb's code" simply because you're (sometimes) not running his code (e.g. when you're in a syscall). Madness runs down that way. For what it's worth, most of the qmail smtpd patches I've seen to add SMTP AUTH (including the one I wrote nearly twenty years ago) are sensible, integrate well with the rest of qmail. You might not get djb's warrantee, but I can't believe you gain nothing by starting from a solid foundation.
- sigil 7y ago
  > You don't find that vulnerability in qmail because qmail doesn't have that feature. But being selective about what features to add is itself a valid strategy for writing secure software — perhaps even the most effective one!
  - deleted 7y ago
    [deleted]
  - pilif 7y ago
    I agree. But if the software is lacking essential features so that everybody patches them back in it's a very ineffective strategy because anybody's home-grown patches are worse than properly maintained features. I can put a machine on the net with a closed port 25. That's the most minimal implementation of an MTA and it's entirely secure. Guaranteed. The thing is that qmail was severely lacking features back in the 90ies and it has received zero feature additions by its original author since then, so it's safe to assume that it's now lacking even more features to the point where anybody running qmail these days is nearly guaranteed to be running franken-qmail full of third-party patches which are surely less well maintained than proper Postfix. That was my point.