Opened 6 years ago

Closed 6 years ago

Last modified 6 years ago

#10365 closed defect (fixed)

Disallow odd-length VERSIONS cells

Reported by: nickm Owned by:
Priority: Medium Milestone: Tor: 0.2.5.x-final
Component: Core Tor/Tor Version:
Severity: Keywords: tor-relay
Cc: Actual Points:
Parent ID: Points:
Reviewer: Sponsor:

Description

Right now, if we receive an odd-length VERSION cell, we ignore the final byte. That's not documented in our spec, though, and doesn't seem to be actually good for anything.

We could just reject all such cells without breaking any current correct Tor server or client, and we probably should. Reported by bobnomnom.

Child Tickets

Attachments (2)

Change History (10)

comment:1 Changed 6 years ago by rl1987

Status: newneeds_review

comment:2 Changed 6 years ago by nickm

I don't think "ignore" is the right answer here; it seems like a close-the-connection thing to me, since it the handshake simply won't work if VERSIONS has been dropped.

comment:3 Changed 6 years ago by nickm

Status: needs_reviewneeds_revision

comment:4 Changed 6 years ago by rl1987

Status: needs_revisionneeds_review

comment:5 Changed 6 years ago by nickm

Resolution: fixed
Status: needs_reviewclosed

Added some parenthesis for paranoia-proofing, tweaked the commit message, and committed to master. Thanks!

comment:6 Changed 6 years ago by arma

Is this the sort of thing that wants a spec change too?

comment:7 in reply to:  6 Changed 6 years ago by nickm

Replying to arma:

Is this the sort of thing that wants a spec change too?

I'm not sure, so I did it anyway in 238555d.

comment:8 Changed 6 years ago by nickm

Whoops; I had to rebase. Make that 4e3894c7808a771f.

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