CVE-2022-31100

rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result. This is a security concern for you, if your service parses untrusted rulex expressions (expressions provided by an untrusted user), and your service becomes unavailable when the thread running rulex panics. The crashes are fixed in version 0.4.3. Affected users are advised to update to this version. The only known workaround for this issue is to assume that regular expression parsing will panic and to add logic to catch panics.

rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result. This is a security concern for you, if your service parses untrusted rulex expressions (expressions provided by an untrusted user), and your service becomes unavailable when the thread running rulex panics. The crashes are fixed in version 0.4.3. Affected users are advised to update to this version. The only known workaround for this issue is to assume that regular expression parsing will panic and to add logic to catch panics.

Impact

When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result.

This is a security concern for you, if

• your service parses untrusted rulex expressions (expressions provided by an untrusted user), and
• your service becomes unavailable when the thread running rulex panics.

Patches

The crashes are fixed in version 0.4.3. Affected users are advised to update to this version.

Workarounds

You can use catch_unwind to recover from panics.

For more information

If you have any questions or comments about this advisory:

• Open an issue in rulex
• Email me at [email protected]

Credits

Credit for finding these bugs goes to

• cargo fuzz and afl.rs
• evanrichter
• ForAllSecure Mayhem

rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result. This is a security concern for you, if your service parses untrusted rulex expressions (expressions provided by an untrusted user), and your service becomes unavailable when the thread running rulex panics. The crashes are fixed in version 0.4.3. Affected users are advised to update to this version. The only known workaround for this issue is to assume that regular expression parsing will panic and to add logic to catch panics.

rulex is a new, portable, regular expression language. When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result. This is a security concern for you, if your service parses untrusted rulex expressions (expressions provided by an untrusted user), and your service becomes unavailable when the thread running rulex panics. The crashes are fixed in version 0.4.3. Affected users are advised to update to this version. The only known workaround for this issue is to assume that regular expression parsing will panic and to add logic to catch panics.

Impact

When parsing untrusted rulex expressions, rulex may crash, possibly enabling a Denial of Service attack. This happens when the expression contains a multi-byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result.

This is a security concern for you, if

• your service parses untrusted rulex expressions (expressions provided by an untrusted user), and
• your service becomes unavailable when the thread running rulex panics.

Patches

The crashes are fixed in version 0.4.3. Affected users are advised to update to this version.

Workarounds

You can use catch_unwind to recover from panics.

For more information

If you have any questions or comments about this advisory:

• Open an issue in rulex
• Email me at [email protected]

Credits

Credit for finding these bugs goes to

• cargo fuzz and afl.rs
• evanrichter
• ForAllSecure Mayhem

When parsing untrusted rulex expressions, rulex may panic, possibly enabling a Denial of Service attack. This happens when the expression contains a multi- byte UTF-8 code point in a string literal or after a backslash, because rulex tries to slice into the code point and panics as a result.

The flaw was corrected in commits fac6d58b25 and 330b3534e7 by using len_utf8() to derive character width in bytes instead of assuming ASCII encoding of 1 byte per char.