Dproxy-nexgen: Inconsistent Interpretation of HTTP Requests
CVE-2022-33988 is a high-severity inconsistent interpretation of HTTP requests vulnerability in Dproxy-nexgen from Dproxy-nexgen Project, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. There is no confirmed exploitation so far. EPSS estimates a 1.23% chance of exploitation within 30 days, higher than 69% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of Dproxy-nexgen you run against the affected versions below, and install the vendor's latest release.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Dproxy-nexgen Project | Dproxy-nexgen | Not specified in the record | Not stated |
Version data comes from NVD's product matching. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N. Scored by NVD.
Official description
dproxy-nexgen (aka dproxy nexgen) re-uses the DNS transaction id (TXID) value from client queries, which allows attackers (able to send queries to the resolver) to conduct DNS cache-poisoning attacks because the TXID value is known to the attacker.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Inconsistent Interpretation of HTTP Requests
The product acts as an intermediary HTTP agent (such as a proxy or firewall) in the data flow between two entities such as a client and server, but it does not interpret malformed HTTP requests or responses in ways that are consistent with how the messages will be processed by those entities that are at the ultimate destination.
How developers prevent this class of flaw
- Use a web server that employs a strict HTTP parsing procedure, such as Apache.
- Terminate the client session after each request.
More Inconsistent Interpretation of HTTP Requests vulnerabilities (CWE-444)
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- sourceforge.net/projects/dproxy/Product, Third Party Advisory
- usenix.org/conference/usenixsecurity22/presentation/jeitnerThird Party Advisory
Technical write-ups (may include proof of concept)
- openwall.com/lists/oss-security/2022/08/14/3Exploit, Mailing List, Third Party Advisory
Recent Inconsistent Interpretation of HTTP Requests vulnerabilities
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 8.1 High severity
- 7.5 High severity
- 9.8 Critical severity
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