SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2021-43557

This makes it possible to construct a URI to bypass the block list on some occasions.

HIGH 7.5EPSS 12.7%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 12.7%, higher than 96% of all known CVEs. Patch or mitigate before the next change window.

Description

The uri-block plugin in Apache APISIX before 2.10.2 uses $request_uri without verification. The $request_uri is the full original request URI without normalization. This makes it possible to construct a URI to bypass the block list on some occasions. For instance, when the block list contains "^/internal/", a URI like `//internal/` can be used to bypass it. Some other plugins also have the same issue. And it may affect the developer's custom plugin.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS
12.74% probability · 96th percentile
CISA KEV
Not listed
Weakness
CWE-77
Affected
apache/apisix
Source
security@apache.org

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.