NetWeaver Application Server for ABAP and ABAP…: Improper Limitation of a Pathname to a Restricted Directory
CVE-2023-27269 is a critical-severity improper limitation of a pathname to a restricted directory vulnerability in NetWeaver Application Server for ABAP and ABAP Platform from SAP, with a CVSS 3.1 base score of 9.6 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. Affected NetWeaver Application Server for ABAP and ABAP Platform versions: 700; 701; 702, 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 0.98% chance of exploitation within 30 days, higher than 63% of scored CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Check which version of NetWeaver Application Server for ABAP and ABAP Platform 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.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| SAP | NetWeaver Application Server for ABAP and ABAP Platform | 700; 701; 702; 731; 740; 750; 751; 752; and 6 more ranges | Not stated |
| SAP | Netweaver Application Server Abap | 700; 701; 702; 731; 740; 750; 751; 752; and 6 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
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- NoneNo data is disclosed.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 9.6 | Critical | CNA (sap.com) |
| CVSS 3.1 | 9.6 | Critical | NVD |
Official description
SAP NetWeaver Application Server for ABAP and ABAP Platform - versions 700, 701, 702, 731, 740, 750, 751, 752, 753, 754, 755, 756, 757, 791, allows an attacker with non-administrative authorizations to exploit a directory traversal flaw in an available service to overwrite the system files. In this attack, no data can be read but potentially critical OS files can be overwritten making the system unavailable.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Limitation of a Pathname to a Restricted Directory
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
How developers prevent this class of flaw
- For any security checks that are performed on the client side, ensure that these checks are duplicated on the server side, in order to avoid CWE-602. Attackers can bypass the client-side checks by modifying values after the checks have been performed, or by changing the client to remove the client-side checks entirely. Then, these modified values would be submitted to the server.
- Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
- Use an application firewall that can detect attacks against this weakness. It can be beneficial in cases in which the code cannot be fixed (because it is controlled by a third party), as an emergency prevention measure while more comprehensive software assurance measures are applied, or to provide defense in depth.
More Improper Limitation of a Pathname to a Restricted Directory vulnerabilities (CWE-22)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Other references
- launchpad.support.sap.com/#/notes/3294595Permissions Required
Recent Improper Limitation of a Pathname to a Restricted Directory vulnerabilities
- 7.5 High severity
- 8.8 High severity
- 9.6 Critical severity
- 8.1 High severity
- 7.5 High severity
- 7.5 High severity
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