Skip to content

fix: encode possible binary characters from user input in audit logs #3464

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Nov 14, 2025
Merged

fix: encode possible binary characters from user input in audit logs #3464

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
85384fe
Encode possible binary characters from user input in audit logs
airween Nov 13, 2025
102275f
Encode possible binary characters in headers; add more tests
airween Nov 13, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
4 changes: 2 additions & 2 deletions src/operators/operator.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -112,15 +112,15 @@ std::string Operator::resolveMatchMessage(Transaction *t,
if (m_couldContainsMacro == false) {
ret = "Matched \"Operator `" + m_op + "' with parameter `" +
utils::string::limitTo(200, m_param) +
"' against variable `" + key + "' (Value: `" +
"' against variable `" + utils::string::toHexIfNeeded(key) + "' (Value: `" +
utils::string::limitTo(100,
utils::string::toHexIfNeeded(value)) + \
"' )";
} else {
std::string p(m_string->evaluate(t));
ret = "Matched \"Operator `" + m_op + "' with parameter `" +
utils::string::limitTo(200, p) +
"' against variable `" + key + "' (Value: `" +
"' against variable `" + utils::string::toHexIfNeeded(key) + "' (Value: `" +
utils::string::limitTo(100,
utils::string::toHexIfNeeded(value)) +
"' )";
Expand Down
6 changes: 3 additions & 3 deletions src/transaction.cc
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1610,7 +1610,7 @@ std::string Transaction::toJSON(int parts) {

if (parts & audit_log::AuditLog::CAuditLogPart) {
// FIXME: check for the binary content size.
LOGFY_ADD("body", this->m_requestBody.str());
LOGFY_ADD("body", utils::string::toHexIfNeeded(this->m_requestBody.str()));
}

/* request headers */
Expand All @@ -1622,7 +1622,7 @@ std::string Transaction::toJSON(int parts) {

m_variableRequestHeaders.resolve(&l);
for (auto &h : l) {
LOGFY_ADD(h->getKey().c_str(), h->getValue());
LOGFY_ADD(utils::string::toHexIfNeeded(h->getKey().c_str()).c_str(), utils::string::toHexIfNeeded(h->getValue()));
delete h;
}

Expand Down Expand Up @@ -1712,7 +1712,7 @@ std::string Transaction::toJSON(int parts) {
LOGFY_ADD("ruleId", std::to_string(a.m_rule.m_ruleId));
LOGFY_ADD("file", a.m_rule.getFileName());
LOGFY_ADD("lineNumber", std::to_string(a.m_rule.getLineNumber()));
LOGFY_ADD("data", a.m_data);
LOGFY_ADD("data", utils::string::toHexIfNeeded(a.m_data));
LOGFY_ADD("severity", std::to_string(a.m_severity));
LOGFY_ADD("ver", a.m_rule.m_ver);
LOGFY_ADD("rev", a.m_rule.m_rev);
Expand Down
186 changes: 186 additions & 0 deletions test/test-cases/regression/auditlog.json
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -536,5 +536,191 @@
"SecAuditLogType Serial",
"SecAuditLogRelevantStatus \"^(?:5|4(?!04))\""
]
},
{
"enabled": 1,
"version_min": 300000,
"version_max": 0,
"title": "auditlog : Binary char from input, check message",
"client": {
"ip": "200.249.12.31",
"port": 2313
},
"server": {
"ip": "200.249.12.31",
"port": 80
},
"request": {
"headers": {
"Host": "www.modsecurity.org",
"User-Agent": "Mozilla\/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko\/20091102 Firefox\/3.5.5 (.NET CLR 3.5.30729)",
"Accept": "text\/html,application\/xhtml+xml,application\/xml;q=0.9,*\/*;q=0.8",
"Accept-Language": "en-us,en;q=0.5",
"Accept-Encoding": "gzip,deflate",
"Accept-Charset": "ISO-8859-1,utf-8;q=0.7,*;q=0.7",
"Keep-Alive": "300",
"Connection": "keep-alive",
"Pragma": "no-cache",
"Cache-Control": "no-cache"
},
"uri": "\/?%ADd+allow%3d1+%ADd+auto",
"method": "GET",
"http_version": 1.1,
"body": ""
},
"response": {
"headers": {
"Content-Type": "plain\/text\n\r"
},
"body": [
"test"
]
},
"expected": {
"audit_log": "\"match\":\"Matched \\\\\"Operator `ValidateUtf8Encoding' with parameter `' against variable `ARGS_NAMES:\\\\\\\\xadd allow=1 \\\\\\\\xadd auto' \\(Value: `\\\\\\\\xadd allow=1 \\\\\\\\xadd auto' \\)\"",
"debug_log": "",
"error_log": "",
"http_code": 403
},
"rules": [
"SecRuleEngine On",
"SecRule REQUEST_FILENAME|ARGS|ARGS_NAMES \"@validateUtf8Encoding\" \"id:920250,phase:2,deny,t:none,msg:'UTF8 Encoding Abuse Attack Attempt',logdata:'%{MATCHED_VAR}'",
"SecAuditEngine RelevantOnly",
"SecAuditLogParts ABHJZ",
"SecAuditLogFormat JSON",
"SecAuditLogStorageDir /tmp/test",
"SecAuditLog /tmp/audit_test_prefix.log",
"SecAuditLogDirMode 0766",
"SecAuditLogFileMode 0600",
"SecAuditLogType Serial",
"SecAuditLogRelevantStatus \"^(?:5|4(?!04))\""
]
},
{
"enabled": 1,
"version_min": 300000,
"version_max": 0,
"title": "auditlog : Binary char from input, check body",
"client": {
"ip": "200.249.12.31",
"port": 2313
},
"server": {
"ip": "200.249.12.31",
"port": 80
},
"request": {
"headers": {
"Host": "www.modsecurity.org",
"User-Agent": "Mozilla\/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko\/20091102 Firefox\/3.5.5 (.NET CLR 3.5.30729)",
"Accept": "text\/html,application\/xhtml+xml,application\/xml;q=0.9,*\/*;q=0.8",
"Accept-Language": "en-us,en;q=0.5",
"Accept-Encoding": "gzip,deflate",
"Accept-Charset": "ISO-8859-1,utf-8;q=0.7,*;q=0.7",
"Keep-Alive": "300",
"Connection": "keep-alive",
"Pragma": "no-cache",
"Cache-Control": "no-cache",
"Content-Type": "application/x-www-form-urlencoded",
"Content-Length": "3"
},
"uri": "\/?attack=true",
"method": "POST",
"http_version": 1.1,
"body": [
"\u00ad=\u00ad"
]
},
"response": {
"headers": {
"Content-Type": "plain\/text\n\r"
},
"body": [
"test"
]
},
"expected": {
"audit_log": "\"body\":\"\\\\\\\\xc2\\\\\\\\xad=\\\\\\\\xc2\\\\\\\\xad\\\\\\\\x0a",
"debug_log": "",
"error_log": "",
"http_code": 403
},
"rules": [
"SecRuleEngine On",
"SecRule ARGS_NAMES \"@rx attack\" \"id:1,phase:2,deny,t:none",
"SecAuditEngine RelevantOnly",
"SecAuditLogParts ABCHJZ",
"SecAuditLogFormat JSON",
"SecAuditLogStorageDir /tmp/test",
"SecAuditLog /tmp/audit_test_prefix.log",
"SecAuditLogDirMode 0766",
"SecAuditLogFileMode 0600",
"SecAuditLogType Serial",
"SecAuditLogRelevantStatus \"^(?:5|4(?!04))\""
]
},
{
"enabled": 1,
"version_min": 300000,
"version_max": 0,
"title": "auditlog : Binary char from input, check header",
"client": {
"ip": "200.249.12.31",
"port": 2313
},
"server": {
"ip": "200.249.12.31",
"port": 80
},
"request": {
"headers": {
"Host": "www.modsecurity.org",
"User-Agent": "Mozilla\/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.1.5) Gecko\/20091102 Firefox\/3.5.5 (.NET CLR 3.5.30729)",
"Accept": "text\/html,application\/xhtml+xml,application\/xml;q=0.9,*\/*;q=0.8",
"Accept-Language": "en-us,en;q=0.5",
"Accept-Encoding": "gzip,deflate",
"Accept-Charset": "ISO-8859-1,utf-8;q=0.7,*;q=0.7",
"Keep-Alive": "300",
"Connection": "keep-alive",
"Pragma": "no-cache",
"Cache-Control": "no-cache",
"Content-Type": "application/x-www-form-urlencoded",
"Content-Length": "3",
"X-\u00ad-custom": "Some \u00ad value"
},
"uri": "\/?attack=true",
"method": "POST",
"http_version": 1.1,
"body": [
"\u00ad=\u00ad"
]
},
"response": {
"headers": {
"Content-Type": "plain\/text\n\r"
},
"body": [
"test"
]
},
"expected": {
"audit_log": "\"X-\\\\\\\\xc2\\\\\\\\xad-custom\":\"Some \\\\\\\\xc2\\\\\\\\xad value\"",
"debug_log": "",
"error_log": "",
"http_code": 403
},
"rules": [
"SecRuleEngine On",
"SecRule ARGS|ARGS_NAMES \"@rx attack\" \"id:1,phase:2,deny,t:none",
"SecAuditEngine RelevantOnly",
"SecAuditLogParts ABHJZ",
"SecAuditLogFormat JSON",
"SecAuditLogStorageDir /tmp/test",
"SecAuditLog /tmp/audit_test_prefix.log",
"SecAuditLogDirMode 0766",
"SecAuditLogFileMode 0600",
"SecAuditLogType Serial",
"SecAuditLogRelevantStatus \"^(?:5|4(?!04))\""
]
}
]
Loading