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Validating that a host is on the correct domain is very hard in the presence of attacks. DNS can be spoofed. If there was an easy way to verify domains, CA-issued SSL certs would be unnecessary.
[1] http://blog.trendmicro.com/trendlabs-security-intelligence/l... [2] https://community.letsencrypt.org/t/attack-on-domain-verific...
Let's Encrypt had a similar vulnerability late last year.[1] That was successfully exploited in a malware attack. There's also a potential BGP attack.[2] Validating that a host is on the correct domain is very hard in the presence of attacks. DNS can be spoofed. If there was an easy way to verify domains, CA-issued SSL certs would be unnecessary. [1] http://blog.trendmicro.com/trendlabs-security-intelligence/l... [2]…
That's quite different. The attackers appear to have had full control of DNS in that case. Being able to control DNS is essentially the definition of domain ownership. Fraudulent issuance would be the smallest problem for a site affected by this. They'd have gotten a certificate from practically any CA issuing DV certificates.
Domain validation is messy and far from perfect, but this vulnerability is just inexcusable.
I distrusted all StartCom certificates anyway after 2014; StartCom is a rogue CA who certify the authenticity of sites which they know have been compromised. Read the story here: https://web.archive.org/web/20140412085458/https://revokame.... (the original page disappeared mysteriously a few days after the story was published). And the HN thread about the incident: https://news.ycombinator.com/item?id=7577290
Startcom is unsafe, unethical, and the kiss of death for a CA, cannot be trusted.
* Applications -> Utilities -> Keychain Access
* Select System Roots on the top bar, then Certificates on the bottom one
* Double click on the 3 StartCom certificates in the list, and flag them as "Never Trust".
Verify by trying to access https://startssl.com
I distrusted all StartCom certificates anyway after 2014; StartCom is a rogue CA who certify the authenticity of sites which they know have been compromised. Read the story here: https://web.archive.org/web/20140412085458/https://revokame.... (the original page disappeared mysteriously a few days after the story was published). And the HN thread about the incident: https://news.ycombinator.com/item?id=7577290
Intentionally publishing something is diametrically opposed to having something compromised.
That was simply an attempt to shirk his contractual obligations with StartCom and get internet points at the same time.
Let's Encrypt had a similar vulnerability late last year.[1] That was successfully exploited in a malware attack. There's also a potential BGP attack.[2] Validating that a host is on the correct domain is very hard in the presence of attacks. DNS can be spoofed. If there was an easy way to verify domains, CA-issued SSL certs would be unnecessary. [1] http://blog.trendmicro.com/trendlabs-security-intelligence/l... [2]…
The Startcom vulnerabilities, on the other hand, are much easier to exploit and clearly violate DV's threat model.
I can't believe that they not only decided not to implement ACME (the protocol behind Let's Encrypt), but also not to at least reuse large portions of ACME, like the way HTTP ownership validation was implemented. It's simply mind-boggling how they would discard a protocol that has received a lot of attention from various security experts. What's more, this design could not have been reviewed by anyone familiar with h…
This is basically saying the CA's private key has been leaked. Because the end result is the same: I can now issue a certificate for any damn domain I want and have it trusted.
The certificate authority system is broken.
Is there any way to semi-blacklist CAs in the browser? I'd like to be warned about certificates from certain CAs without access to that site being blocked. That way I can still reach these sites, but know not to trust them with confidential data. It also allows me to ask those sites to use a CA I trust. The point being to be able to punish CAs less harshly than the death-sentence that is root removal.
http://www.techfleece.com/2011/09/09/how-to-delete-the-digin...
I distrusted all StartCom certificates anyway after 2014; StartCom is a rogue CA who certify the authenticity of sites which they know have been compromised. Read the story here: https://web.archive.org/web/20140412085458/https://revokame.... (the original page disappeared mysteriously a few days after the story was published). And the HN thread about the incident: https://news.ycombinator.com/item?id=7577290
That publicity stunt by some over-zealous guy cannot be called a "compromised key". Intentionally publishing something is diametrically opposed to having something compromised. That was simply an attempt to shirk his contractual obligations with StartCom and get internet points at the same time.
Also, the flip side of this is that occasionally (but very rarely), people want their private key to be a publicly accessible. See http://readme.localtest.me/, where everything else .localtest.me resolves to 127.0.0.1, and they tried to post a wildcard, but it got revoked.