https://github.com/curl/curl: Server-Side Request Forgery
CVE-2022-27780 is a high-severity server-side request forgery vulnerability in https://github.com/curl/curl, 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. Affected https://github.com/curl/curl versions: Fixed in 7.83.1. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 2.52% chance of exploitation within 30 days, higher than 85% of scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update curl to 7.86.0 or a later version.
- Update SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
- Update SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP to V3.1.5 or a later version.
- 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 |
|---|---|---|---|
| Https://github.com/curl/curl | https://github.com/curl/curl | Fixed in 7.83.1 | Not stated |
| Haxx | curl | before 7.86.0 | 7.86.0 |
| NetApp | solidfire_\&_hci_storage_node | 0 | Not stated |
| NetApp | ontap_9 | 0 | Not stated |
| NetApp | solidfire_\&_hci_management_node | h300s; h410s; h500s; h700s; 0 | Not stated |
| NetApp | hci_bootstrap_os | 0 | Not stated |
| Siemens | SIMATIC S7-1500 CPU 1518-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Siemens | SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| Siemens | SIPLUS S7-1500 CPU 1518-4 PN/DP MFP | V3.1.0 up to, but not including, V3.1.5 | V3.1.5 |
| NetApp | Clustered Data Ontap | Not specified in the record | Not stated |
| NetApp | Solidfire, Enterprise Sds & Hci Storage Node | Not specified in the record | Not stated |
| NetApp | H410s Firmware | Not specified in the record | Not stated |
| NetApp | H700s Firmware | Not specified in the record | Not stated |
| NetApp | H500s Firmware | Not specified in the record | Not stated |
| NetApp | H300s Firmware | Not specified in the record | Not stated |
| Splunk | Universal Forwarder | 8.2.0 up to, but not including, 8.2.12; 9.0.0 up to, but not including, 9.0.6; 9.1.0 | 8.2.12, 9.0.6 |
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
- 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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.5 | High | NVD |
| CVSS 3.1 | 5.3 | Medium | CISA (ADP) |
| CVSS 2.0 | 5.0 | Medium | NVD |
Official description
The curl URL parser wrongly accepts percent-encoded URL separators like '/'when decoding the host name part of a URL, making it a *different* URL usingthe wrong host name when it is later retrieved.For example, a URL like `http://example.com%2F127.0.0.1/`, would be allowed bythe parser and get transposed into `http://example.com/127.0.0.1/`. This flawcan be used to circumvent filters, checks and more.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Server-Side Request Forgery
The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.
How developers prevent this class of flaw
- If there is a known list of applications, IP, hostname, and/or domains to which the product is allowed to communicate, then use allowlists to ensure that outgoing requests are restricted to these known entities. The allowlists could be in the application code or possibly enforced by firewalls or network segmentation.
- If the product is expected to be able to connect to arbitrary IP addresses or domains, consider using a denylist that includes private network addresses, internal domain names, etc. The denylist could be in the application code or possibly enforced by firewalls or network segmentation.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: poc, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Third-party and government advisories
- security.gentoo.org/glsa/202212-01Third Party Advisory
- security.netapp.com/advisory/ntap-20220609-0009/Third Party Advisory
Technical write-ups (may include proof of concept)
- hackerone.com/reports/1553841Exploit, Third Party Advisory
Other references
Other vulnerabilities in https://github.com/curl/curl
- 7.5 High severity
- 8.8 High severity
- 8.8 High severity
- 9.1 Critical severity
- 7.5 High severity
- 9.8 Critical severity
Recent Server-Side Request Forgery vulnerabilities
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
- 7.5 High severity
- 9.8 Critical severity
- 7.5 High severity
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