CyberSecBulletin
CVE-2022-3786NVD status: Modified

OpenSSL: Buffer Copy without Checking Size of Input

Published Updated By the CyberSecBulletin desk

CVE-2022-3786 is a high-severity buffer copy without checking size of input vulnerability in OpenSSL, 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. The record lists version 3.0.7 as the first without the flaw, so updating OpenSSL to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 92.5% chance of exploitation within 30 days, which is in the top 0.17% of all scored CVEs.

Patch now

Exploitation in the next 30 days is more likely than not, according to EPSS.

What to do

  1. Update OpenSSL to 3.0.7 or a later version.
  2. Update Calibre ICE to V2023.1 or a later version.
  3. Update Mcenter to V5.3.0 or a later version.
  4. Read the advisory on git.openssl.org for workarounds and exact fixed builds.
  5. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
OpenSSLOpenSSL3.0.0 up to, but not including, 3.0.73.0.7
SiemensCalibre ICEV2022.4 up to, but not including, V2023.1V2023.1
SiemensMcenterV5.2.1 up to, but not including, V5.3.0V5.3.0
SiemensSCALANCE X204RNA (HSR)V3.2.7 up to, but not including, V3.2.8V3.2.8
SiemensSCALANCE X204RNA (PRP)V3.2.7 up to, but not including, V3.2.8V3.2.8
SiemensSCALANCE X204RNA EEC (HSR)V3.2.7 up to, but not including, V3.2.8V3.2.8
SiemensSCALANCE X204RNA EEC (PRP)V3.2.7 up to, but not including, V3.2.8V3.2.8
SiemensSCALANCE X204RNA EEC (PRP/HSR)V3.2.7 up to, but not including, V3.2.8V3.2.8
SiemensSICAM GridPassV1.80 up to, but not including, V2.20V2.20
SiemensSIMATIC RTLS Locating ManagerV2.13.0.0 up to, but not including, V2.13.0.3V2.13.0.3
Fedora ProjectFedora36; 37Not stated
Node.jsNode.js18.0.0 up to, but not including, 18.11.0; 18.12.0; 19.0.018.11.0

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
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.5HighNVD
CVSS 3.17.5HighCISA (ADP)

Official description

A buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Note that this occurs after certificate chain signature verification and requires either a CA to have signed a malicious certificate or for an application to continue certificate verification despite failure to construct a path to a trusted issuer. An attacker can craft a malicious email address in a certificate to overflow an arbitrary number of bytes containing the `.' character (decimal 46) on the stack. This buffer overflow could result in a crash (causing a denial of service). In a TLS client, this can be triggered by connecting to a malicious server. In a TLS server, this can be triggered if the server requests client authentication and a malicious client connects.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Buffer Copy without Checking Size of Input

The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Buffer Copy without Checking Size of Input vulnerabilities (CWE-120)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in OpenSSL

All OpenSSL vulnerabilities

Recent Buffer Copy without Checking Size of Input vulnerabilities

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