SAP Web Dispatcher: Inconsistent Interpretation of HTTP Requests
CVE-2023-33987 is a critical-severity inconsistent interpretation of HTTP requests vulnerability in SAP Web Dispatcher from SAP, with a CVSS 3.1 base score of 9.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected SAP Web Dispatcher versions: WEBDISP 7.49; WEBDISP 7.53; WEBDISP 7.54, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.69% chance of exploitation within 30 days, higher than 53% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of SAP Web Dispatcher you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on sap.com for workarounds and exact fixed builds.
- 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 |
|---|---|---|---|
| SAP | SAP Web Dispatcher | WEBDISP 7.49; WEBDISP 7.53; WEBDISP 7.54; WEBDISP 7.77; WEBDISP 7.81; WEBDISP 7.85; WEBDISP 7.88; WEBDISP 7.89; and 15 more ranges | Not stated |
| SAP | Web Dispatcher | 7.49; 7.53; 7.54; 7.77; 7.81; 7.85; 7.88; 7.89; and 16 more ranges | Not stated |
Version data comes from the organisation that assigned the CVE. 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
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.6 | High | CNA (sap.com) |
| CVSS 3.1 | 9.4 | Critical | NVD |
Official description
An unauthenticated attacker in SAP Web Dispatcher - versions WEBDISP 7.49, WEBDISP 7.53, WEBDISP 7.54, WEBDISP 7.77, WEBDISP 7.81, WEBDISP 7.85, WEBDISP 7.88, WEBDISP 7.89, WEBDISP 7.90, KERNEL 7.49, KERNEL 7.53, KERNEL 7.54 KERNEL 7.77, KERNEL 7.81, KERNEL 7.85, KERNEL 7.88, KERNEL 7.89, KERNEL 7.90, KRNL64NUC 7.49, KRNL64UC 7.49, KRNL64UC 7.53, HDB 2.00, XS_ADVANCED_RUNTIME 1.00, SAP_EXTENDED_APP_SERVICES 1, can submit a malicious crafted request over a network to a front-end server which may, over several attempts, result in a back-end server confusing the boundaries of malicious and legitimate messages. This can result in the back-end server executing a malicious payload which can be used to read or modify information on the server or make it temporarily unavailable.
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.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
- me.sap.com/notes/3233899Permissions Required
Other vulnerabilities in SAP Web Dispatcher
- 10.0 Critical severity
- 7.7 High severity
- 8.8 High severity
- 9.8 Critical severity
- 7.5 High severity
- 9.4 Critical severity
Recent Inconsistent Interpretation of HTTP Requests vulnerabilities
- 9.1 Critical severity
- 7.3 High severity
- 9.1 Critical severity
- 9.1 Critical severity
- 9.8 Critical severity
- 7.5 High severity
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