SIMATIC S7-1500 CPU 1518-4 PN/DP MFP: Integer Overflow or Wraparound
CVE-2022-42898 is a high-severity integer overflow or wraparound vulnerability in SIMATIC S7-1500 CPU 1518-4 PN/DP MFP from Siemens, with a CVSS 3.1 base score of 8.8 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. The record lists version V3.1.5 as the first without the flaw, so updating SIMATIC S7-1500 CPU 1518-4 PN/DP MFP to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 6.86% chance of exploitation within 30 days, which is in the top 5.85% of all scored CVEs.
High severity with no evidence of exploitation so far.
What to do
- 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.
- Update SIPLUS S7-1500 CPU 1518-4 PN/DP MFP to V3.1.5 or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| 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 |
| Mit | Kerberos 5 | 1.8 up to, but not including, 1.19.4; 1.20 | 1.19.4 |
| Heimdal Project | Heimdal | before 7.7.1 | 7.7.1 |
| Samba | Samba | before 4.15.12; 4.16.0 up to, but not including, 4.16.7; 4.17.0 up to, but not including, 4.17.3 | 4.15.12, 4.16.7, 4.17.3 |
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
- 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
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 8.8 | High | NVD |
| CVSS 3.1 | 8.8 | High | CISA (ADP) |
Official description
PAC parsing in MIT Kerberos 5 (aka krb5) before 1.19.4 and 1.20.x before 1.20.1 has integer overflows that may lead to remote code execution (in KDC, kadmind, or a GSS or Kerberos application server) on 32-bit platforms (which have a resultant heap-based buffer overflow), and cause a denial of service on other platforms. This occurs in krb5_pac_parse in lib/krb5/krb/pac.c. Heimdal before 7.7.1 has "a similar bug."
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Integer Overflow or Wraparound
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
How developers prevent this class of flaw
- Ensure that all protocols are strictly defined, such that all out-of-bounds behavior can be identified simply, and require strict conformance to the protocol.
- Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. If possible, choose a language or compiler that performs automatic bounds checking.
- 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 libraries or frameworks that make it easier to handle numbers without unexpected consequences. Examples include safe integer handling packages such as SafeInt (C++) or IntegerLib (C or C++).
More Integer Overflow or Wraparound vulnerabilities (CWE-190)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Patches and release notes
- bugzilla.samba.org/show_bug.cgi?id=15203Exploit, Issue Tracking, Third Party Advisory
- github.com/krb5/krb5/commit/ea92d2f0fcceb54a70910fa32e9a0d7a5afc3583Third Party Advisory
Third-party and government advisories
- samba.org/samba/security/CVE-2022-42898.htmlThird Party Advisory
Other references
Other vulnerabilities in SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
- 9.6 Critical severity
- 9.6 Critical severity
- 9.6 Critical severity
- 7.8 High severity
- 7.1 High severity
- 9.1 Critical severity
Recent Integer Overflow or Wraparound vulnerabilities
- 8.6 High severity
- 8.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 9.8 Critical severity
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