GHSA-3633-r77q-h3v3: Pip/ddtrace vulnerability
Summary
A regular expression used to obfuscate URL query strings can consume excessive CPU when processing certain attacker-controlled input. This can stall request processing and cause denial of service in applications using affected HTTP tracing integrations.
Details
The default query-string obfuscation pattern can exhibit excessive backtracking. The pattern is applied synchronously when recording HTTP URL metadata, allowing query-string processing to occupy application resources for an extended period.
As a workaround, set both DDTRACEOBFUSCATIONQUERYSTRINGREGEXP and DDTRACEOBFUSCATIONQUERYSTRINGPATTERN to the fixed Python-compatible regex below, then restart the application. Setting both variables covers all affected ddtrace versions, including releases before 1.19.0.
export DDTRACEOBFUSCATIONQUERYSTRINGREGEXP='(?i)(?:(?:"|%22)?)(?:(?:old[-]?|new[-]?)?p(?:ass)?w(?:or)?d(?:1|2)?|pass(?:[-]?phrase)?|secret|(?:api[-]?|private[-]?|public[-]?|access[-]?|secret[-]?|app(?:lication)?[-]?)key(?:[-]?id)?|token|consumer[-]?(?:id|key|secret)|sign(?:ed|ature)?|auth(?:entication|orization)?)(?:(?:\s|%20)(?:=|%3D)[^&]+|(?:"|%22)(?:\s|%20)(?::|%3A)(?:\s|%20)(?:"|%22)(?:%2[^2]|%[^2]|[^"%])+(?:"|%22))|(?:bearer(?:\s|%20)+[a-z0-9.\-]+|token(?::|%3A)[a-z0-9]{13}|gh[opsu][0-9a-zA-Z]{36}|(?:(?<![\w-])|(?<=%[0-9a-f]{2}))ey[I-L][\w-]+(?:=|%3D)\.ey[I-L][\w-]+(?:=|%3D)(?:\.(?:[\w.+/=-]|%3D|%2F|%2B)+)?|-{5}BEGIN(?:[a-z\s]|%20)+PRIVATE(?:\s|%20)KEY-{5}[^\-]+-{5}END(?:[a-z\s]|%20)+PRIVATE(?:\s|%20)KEY(?:-{5})?(?:\n|%0A)?|(?:ssh-(?:rsa|dss)|ecdsa-[a-z0-9]+-[a-z0-9]+)(?:\s|%20|%09)+(?:[a-z0-9/.+]|%2F|%5C|%2B){100,}(?:=|%3D)(?:(?:\s|%20|%09)+[a-z0-9.-]+)?)'
export DDTRACEOBFUSCATIONQUERYSTRINGPATTERN="$DDTRACEOBFUSCATIONQUERYSTRINGREGEXP"
Proof of concept
Detailed triggering inputs and reproduction steps are omitted from this advisory. The patched version includes regression coverage for the affected behavior.
Impact
Regular expression denial of service (ReDoS) affecting applications that process attacker-controlled URL query strings through the vulnerable obfuscation pattern. Successful exploitation can cause excessive CPU consumption, prolonged request latency, and service unavailability.
The vulnerable processing is enabled by default for affected HTTP integrations that include query strings in URL span tags.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
pip/ddtraceto a version that resolves this vulnerability.Fixed in 4.15.6 - Upgrade
Upgrade
pip/ddtraceto a version that resolves this vulnerability.Fixed in 3.19.9 - Configuration
Set both DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP and DD_TRACE_OBFUSCATION_QUERY_STRING_PATTERN to the fixed Python-compatible regular expression shown, then restart the application.
ddtrace URL query-string obfuscation DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP and DD_TRACE_OBFUSCATION_QUERY_STRING_PATTERN = (?i)(?:(?:"|%22)?)(?:(?:old[-_]?|new[-_]?)?p(?:ass)?w(?:or)?d(?:1|2)?|pass(?:[-_]?phrase)?|secret|(?:api[-_]?|private[-_]?|public[-_]?|access[-_]?|secret[-_]?|app(?:lication)?[-_]?)key(?:[-_]?id)?|token|consumer[-_]?(?:id|key|secret)|sign(?:ed|ature)?|auth(?:entication|orization)?)(?:(?:\s|%20)*(?:=|%3D)[^&]+|(?:"|%22)(?:\s|%20)*(?::|%3A)(?:\s|%20)*(?:"|%22)(?:%2[^2]|%[^2]|[^"%])+(?:"|%22))|(?:bearer(?:\s|%20)+[a-z0-9._\-]+|token(?::|%3A)[a-z0-9]{13}|gh[opsu]_[0-9a-zA-Z]{36}|(?:(?<![\w-])|(?<=%[0-9a-f]{2}))ey[I-L][\w-]+(?:=|%3D)*\.ey[I-L][\w-]+(?:=|%3D)*(?:\.(?:[\w.+/=-]|%3D|%2F|%2B)+)?|-{5}BEGIN(?:[a-z\s]|%20)+PRIVATE(?:\s|%20)KEY-{5}[^\-]+-{5}END(?:[a-z\s]|%20)+PRIVATE(?:\s|%20)KEY(?:-{5})?(?:\n|%0A)?|(?:ssh-(?:rsa|dss)|ecdsa-[a-z0-9]+-[a-z0-9]+)(?:\s|%20|%09)+(?:[a-z0-9/.+]|%2F|%5C|%2B){100,}(?:=|%3D)*(?:(?:\s|%20|%09)+[a-z0-9._-]+)?)
Event History
Frequently Asked Questions
Which applications are exposed to this denial-of-service condition?
Applications using affected ddtrace HTTP tracing integrations are exposed when they record HTTP URL metadata and process attacker-controlled query strings. The vulnerable query-string obfuscation regex is applied synchronously, so a crafted request can stall request processing.
What does an attacker need to exploit this issue?
An attacker needs to be able to send a request containing a query string that triggers excessive regex backtracking. No other prerequisite is stated in the available information.
Is the default configuration affected?
Yes. The issue is in the default query-string obfuscation pattern.
What can be done if updating ddtrace is not immediately possible?
Set both DD_TRACE_OBFUSCATION_QUERY_STRING_REGEXP and DD_TRACE_OBFUSCATION_QUERY_STRING_PATTERN to the fixed Python-compatible regex provided in the advisory, then restart the application. Setting both variables is intended to cover affected versions, including releases before 1.19.0.