NGINX map directive and regex matching vulnerability
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | |||||||||||||||||||||
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| F5 | NGINX Plus | unknown |
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| F5 | NGINX Open Source | unaffected |
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| Vendor | Product | Versions | ||||||||||||||||||||||||||||
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| F5 | Nginx Open Source |
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| F5 | Nginx Plus |
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Vendor Workaround
To mitigate this vulnerability, do not use unnamed captures. Use named captures instead and limit their usage to the block with the regex match.
| Source | ID | Title |
|---|---|---|
Debian DSA |
DSA-6575-1 | nginx security update |
Ubuntu USN |
USN-8955-1 | nginx vulnerabilities |
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: 1.2% (1.198% probability within 30 days)
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threat_severity
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threat_severity
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| First Time appeared |
F5
F5 nginx Open Source F5 nginx Plus |
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| Vendors & Products |
F5
F5 nginx Open Source F5 nginx Plus |
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ssvc
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| Description | A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and the root directive or access log format references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR. Impact: This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated. | |
| Title | NGINX map directive and regex matching vulnerability | |
| Weaknesses | CWE-122 | |
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cvssV3_1
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