In OpenStack Swift through 2.38.0, the proxy server Accept header parser contains a regular expression vulnerable to catastrophic backtracking (ReDoS). The "qdtext" pattern (?:[^"]|\\.)* allows an unauthenticated remote attacker to send a crafted Accept header that causes exponential CPU consumption in the proxy worker. A payload of 32 backslash-character pairs exceeds 30 seconds of CPU time.
No authentication is required. Repeated requests can exhaust all proxy worker threads, resulting in a complete denial of service.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
None
No privileges needed
User Interaction
None
No user interaction needed
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
High
Complete denial of service
CVSS Vector v4.0
Weakness Type (CWE)
Vulnerable Products 4
| Configuration | From (including) | Up to (excluding) |
|---|---|---|
|
Openstack Swift
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:*
|
1.9.1
|
2.35.4
|
|
Openstack Swift
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:*
|
2.36.0
|
2.36.3
|
|
Openstack Swift
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:*
|
2.37.0
|
2.37.3
|
|
Openstack Swift
cpe:2.3:a:openstack:swift:*:*:*:*:*:*:*:*
|
2.38.0
|
<= 2.38.0
|