prosody
0.11.12
spec/utf8_sequences.txt
Software / code / prosody
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spec/utf8_sequences.txt @ 12181:783056b4e448 0.11 0.11.12
util.xml: Do not allow doctypes, comments or processing instructions
Yes. This is as bad as it sounds. CVE pending.
In Prosody itself, this only affects mod_websocket, which uses util.xml
to parse the <open/> frame, thus allowing unauthenticated remote DoS
using Billion Laughs. However, third-party modules using util.xml may
also be affected by this.
This commit installs handlers which disallow the use of doctype
declarations and processing instructions without any escape hatch. It,
by default, also introduces such a handler for comments, however, there
is a way to enable comments nontheless.
This is because util.xml is used to parse human-facing data, where
comments are generally a desirable feature, and also because comments
are generally harmless.
| author | Jonas Schäfer <jonas@wielicki.name> |
|---|---|
| date | Mon, 10 Jan 2022 18:23:54 +0100 |
| parent | 8236:4878e4159e12 |
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Should pass: 41 42 43 # Simple ASCII - abc Should pass: 41 42 c3 87 # "ABÇ" Should pass: 41 42 e1 b8 88 # "ABḈ" Should pass: 41 42 f0 9d 9c 8d # "AB𝜍" Should pass: F4 8F BF BF # Last valid sequence (U+10FFFF) Should fail: F4 90 80 80 # First invalid sequence (U+110000) Should fail: 80 81 82 83 # Invalid sequence (invalid start byte) Should fail: C2 C3 # Invalid sequence (invalid continuation byte) Should fail: C0 43 # Overlong sequence Should fail: F5 80 80 80 # U+140000 (out of range) Should fail: ED A0 80 # U+D800 (forbidden by RFC 3629) Should fail: ED BF BF # U+DFFF (forbidden by RFC 3629) Should pass: ED 9F BF # U+D7FF (U+D800 minus 1: allowed) Should pass: EE 80 80 # U+E000 (U+D7FF plus 1: allowed) Should fail: C0 # Invalid start byte Should fail: C1 # Invalid start byte Should fail: C2 # Incomplete sequence Should fail: F8 88 80 80 80 # 6-byte sequence Should pass: 7F # Last valid 1-byte sequence (U+00007F) Should pass: DF BF # Last valid 2-byte sequence (U+0007FF) Should pass: EF BF BF # Last valid 3-byte sequence (U+00FFFF) Should pass: 00 # First valid 1-byte sequence (U+000000) Should pass: C2 80 # First valid 2-byte sequence (U+000080) Should pass: E0 A0 80 # First valid 3-byte sequence (U+000800) Should pass: F0 90 80 80 # First valid 4-byte sequence (U+000800) Should fail: F8 88 80 80 80 # First 5-byte sequence - invalid per RFC 3629 Should fail: FC 84 80 80 80 80 # First 6-byte sequence - invalid per RFC 3629 Should pass: EF BF BD # U+00FFFD (replacement character) Should fail: 80 # First continuation byte Should fail: BF # Last continuation byte Should fail: 80 BF # 2 continuation bytes Should fail: 80 BF 80 # 3 continuation bytes Should fail: 80 BF 80 BF # 4 continuation bytes Should fail: 80 BF 80 BF 80 # 5 continuation bytes Should fail: 80 BF 80 BF 80 BF # 6 continuation bytes Should fail: 80 BF 80 BF 80 BF 80 # 7 continuation bytes Should fail: FE # Impossible byte Should fail: FF # Impossible byte Should fail: FE FE FF FF # Impossible bytes Should fail: C0 AF # Overlong "/" Should fail: E0 80 AF # Overlong "/" Should fail: F0 80 80 AF # Overlong "/" Should fail: F8 80 80 80 AF # Overlong "/" Should fail: FC 80 80 80 80 AF # Overlong "/" Should fail: C0 80 AF # Overlong "/" (invalid) Should fail: C1 BF # Overlong Should fail: E0 9F BF # Overlong Should fail: F0 8F BF BF # Overlong Should fail: F8 87 BF BF BF # Overlong Should fail: FC 83 BF BF BF BF # Overlong Should pass: EF BF BE # U+FFFE (invalid unicode, valid UTF-8) Should pass: EF BF BF # U+FFFF (invalid unicode, valid UTF-8)
