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author | Roland Shoemaker <roland@golang.org> | 2021-05-27 10:40:06 -0700 |
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committer | Roland Shoemaker <roland@golang.org> | 2021-05-27 20:29:16 +0000 |
commit | 31d60cda1f58b7558fc5725d2b9e4531655d980e (patch) | |
tree | abe3b35f2a3e7d7b4a14ed712cf30d8b7c5136df /src/net/dnsclient_unix_test.go | |
parent | df9ce19db6df32d94eae8760927bdfbc595433c3 (diff) | |
download | go-31d60cda1f58b7558fc5725d2b9e4531655d980e.tar.gz go-31d60cda1f58b7558fc5725d2b9e4531655d980e.zip |
[release-branch.go1.15] net: verify results from Lookup* are valid domain names
For the methods LookupCNAME, LookupSRV, LookupMX, LookupNS, and
LookupAddr check that the returned domain names are in fact valid DNS
names using the existing isDomainName function.
Thanks to Philipp Jeitner and Haya Shulman from Fraunhofer SIT for
reporting this issue.
Updates #46241
Fixes #46356
Fixes CVE-2021-33195
Change-Id: I47a4f58c031cb752f732e88bbdae7f819f0af4f3
Reviewed-on: https://go-review.googlesource.com/c/go/+/323131
Trust: Roland Shoemaker <roland@golang.org>
Run-TryBot: Roland Shoemaker <roland@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Filippo Valsorda <filippo@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
(cherry picked from commit cdcd02842da7c004efd023881e3719105209c908)
Reviewed-on: https://go-review.googlesource.com/c/go/+/323269
Diffstat (limited to 'src/net/dnsclient_unix_test.go')
-rw-r--r-- | src/net/dnsclient_unix_test.go | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/src/net/dnsclient_unix_test.go b/src/net/dnsclient_unix_test.go index 06553636ee..819f20b887 100644 --- a/src/net/dnsclient_unix_test.go +++ b/src/net/dnsclient_unix_test.go @@ -1799,3 +1799,160 @@ func TestPTRandNonPTR(t *testing.T) { t.Errorf("names = %q; want %q", names, want) } } + +func TestCVE202133195(t *testing.T) { + fake := fakeDNSServer{ + rh: func(n, _ string, q dnsmessage.Message, _ time.Time) (dnsmessage.Message, error) { + r := dnsmessage.Message{ + Header: dnsmessage.Header{ + ID: q.Header.ID, + Response: true, + RCode: dnsmessage.RCodeSuccess, + RecursionAvailable: true, + }, + Questions: q.Questions, + } + switch q.Questions[0].Type { + case dnsmessage.TypeCNAME: + r.Answers = []dnsmessage.Resource{} + case dnsmessage.TypeA: // CNAME lookup uses a A/AAAA as a proxy + r.Answers = append(r.Answers, + dnsmessage.Resource{ + Header: dnsmessage.ResourceHeader{ + Name: dnsmessage.MustNewName("<html>.golang.org."), + Type: dnsmessage.TypeA, + Class: dnsmessage.ClassINET, + Length: 4, + }, + Body: &dnsmessage.AResource{ + A: TestAddr, + }, + }, + ) + case dnsmessage.TypeSRV: + n := q.Questions[0].Name + if n.String() == "_hdr._tcp.golang.org." { + n = dnsmessage.MustNewName("<html>.golang.org.") + } + r.Answers = append(r.Answers, + dnsmessage.Resource{ + Header: dnsmessage.ResourceHeader{ + Name: n, + Type: dnsmessage.TypeSRV, + Class: dnsmessage.ClassINET, + Length: 4, + }, + Body: &dnsmessage.SRVResource{ + Target: dnsmessage.MustNewName("<html>.golang.org."), + }, + }, + ) + case dnsmessage.TypeMX: + r.Answers = append(r.Answers, + dnsmessage.Resource{ + Header: dnsmessage.ResourceHeader{ + Name: dnsmessage.MustNewName("<html>.golang.org."), + Type: dnsmessage.TypeMX, + Class: dnsmessage.ClassINET, + Length: 4, + }, + Body: &dnsmessage.MXResource{ + MX: dnsmessage.MustNewName("<html>.golang.org."), + }, + }, + ) + case dnsmessage.TypeNS: + r.Answers = append(r.Answers, + dnsmessage.Resource{ + Header: dnsmessage.ResourceHeader{ + Name: dnsmessage.MustNewName("<html>.golang.org."), + Type: dnsmessage.TypeNS, + Class: dnsmessage.ClassINET, + Length: 4, + }, + Body: &dnsmessage.NSResource{ + NS: dnsmessage.MustNewName("<html>.golang.org."), + }, + }, + ) + case dnsmessage.TypePTR: + r.Answers = append(r.Answers, + dnsmessage.Resource{ + Header: dnsmessage.ResourceHeader{ + Name: dnsmessage.MustNewName("<html>.golang.org."), + Type: dnsmessage.TypePTR, + Class: dnsmessage.ClassINET, + Length: 4, + }, + Body: &dnsmessage.PTRResource{ + PTR: dnsmessage.MustNewName("<html>.golang.org."), + }, + }, + ) + } + return r, nil + }, + } + + r := Resolver{PreferGo: true, Dial: fake.DialContext} + // Change the default resolver to match our manipulated resolver + originalDefault := DefaultResolver + DefaultResolver = &r + defer func() { + DefaultResolver = originalDefault + }() + + _, err := r.LookupCNAME(context.Background(), "golang.org") + if expected := "lookup golang.org: CNAME target is invalid"; err == nil || err.Error() != expected { + t.Errorf("Resolver.LookupCNAME returned unexpected error, got %q, want %q", err.Error(), expected) + } + _, err = LookupCNAME("golang.org") + if expected := "lookup golang.org: CNAME target is invalid"; err == nil || err.Error() != expected { + t.Errorf("LookupCNAME returned unexpected error, got %q, want %q", err.Error(), expected) + } + + _, _, err = r.LookupSRV(context.Background(), "target", "tcp", "golang.org") + if expected := "lookup golang.org: SRV target is invalid"; err == nil || err.Error() != expected { + t.Errorf("Resolver.LookupSRV returned unexpected error, got %q, want %q", err.Error(), expected) + } + _, _, err = LookupSRV("target", "tcp", "golang.org") + if expected := "lookup golang.org: SRV target is invalid"; err == nil || err.Error() != expected { + t.Errorf("LookupSRV returned unexpected error, got %q, want %q", err.Error(), expected) + } + + _, _, err = r.LookupSRV(context.Background(), "hdr", "tcp", "golang.org") + if expected := "lookup golang.org: SRV header name is invalid"; err == nil || err.Error() != expected { + t.Errorf("Resolver.LookupSRV returned unexpected error, got %q, want %q", err.Error(), expected) + } + _, _, err = LookupSRV("hdr", "tcp", "golang.org") + if expected := "lookup golang.org: SRV header name is invalid"; err == nil || err.Error() != expected { + t.Errorf("LookupSRV returned unexpected error, got %q, want %q", err.Error(), expected) + } + + _, err = r.LookupMX(context.Background(), "golang.org") + if expected := "lookup golang.org: MX target is invalid"; err == nil || err.Error() != expected { + t.Errorf("Resolver.LookupMX returned unexpected error, got %q, want %q", err.Error(), expected) + } + _, err = LookupMX("golang.org") + if expected := "lookup golang.org: MX target is invalid"; err == nil || err.Error() != expected { + t.Errorf("LookupMX returned unexpected error, got %q, want %q", err.Error(), expected) + } + + _, err = r.LookupNS(context.Background(), "golang.org") + if expected := "lookup golang.org: NS target is invalid"; err == nil || err.Error() != expected { + t.Errorf("Resolver.LookupNS returned unexpected error, got %q, want %q", err.Error(), expected) + } + _, err = LookupNS("golang.org") + if expected := "lookup golang.org: NS target is invalid"; err == nil || err.Error() != expected { + t.Errorf("LookupNS returned unexpected error, got %q, want %q", err.Error(), expected) + } + + _, err = r.LookupAddr(context.Background(), "1.2.3.4") + if expected := "lookup 1.2.3.4: PTR target is invalid"; err == nil || err.Error() != expected { + t.Errorf("Resolver.LookupAddr returned unexpected error, got %q, want %q", err.Error(), expected) + } + _, err = LookupAddr("1.2.3.4") + if expected := "lookup 1.2.3.4: PTR target is invalid"; err == nil || err.Error() != expected { + t.Errorf("LookupAddr returned unexpected error, got %q, want %q", err.Error(), expected) + } +} |