CyberSecBulletin
CVE-2024-32475NVD status: Modified

envoy: Incorrect Check of Function Return Value

Published Updated By the CyberSecBulletin desk

CVE-2024-32475 is a high-severity incorrect check of function return value vulnerability in envoy from Envoyproxy, 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 1.27.5 as the first without the flaw, so updating envoy to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.68% chance of exploitation within 30 days, higher than 53% of scored CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update envoy to 1.27.5 or a later version.
  2. Read the advisory on github.com for workarounds and exact fixed builds.
  3. 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
Envoyproxyenvoy>= 1.30.0, < 1.30.1; >= 1.29.0, < 1.29.4; >= 1.28.0, < 1.28.3; >= 1.13.0, < 1.27.5; 1.13.0 up to, but not including, 1.27.51.27.5

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 CNA (github.com).

Official description

Envoy is a cloud-native, open source edge and service proxy. When an upstream TLS cluster is used with `auto_sni` enabled, a request containing a `host`/`:authority` header longer than 255 characters triggers an abnormal termination of Envoy process. Envoy does not gracefully handle an error when setting SNI for outbound TLS connection. The error can occur when Envoy attempts to use the `host`/`:authority` header value longer than 255 characters as SNI for outbound TLS connection. SNI length is limited to 255 characters per the standard. Envoy always expects this operation to succeed and abnormally aborts the process when it fails. This vulnerability is fixed in 1.30.1, 1.29.4, 1.28.3, and 1.27.5.

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

The underlying weakness: Incorrect Check of Function Return Value

The product incorrectly checks a return value from a function, which prevents it from detecting errors or exceptional conditions.

How developers prevent this class of flaw

  • Use a language or compiler that uses exceptions and requires the catching of those exceptions.
  • Properly check all functions which return a value.
  • When designing any function make sure you return a value or throw an exception in case of an error.

More Incorrect Check of Function Return Value vulnerabilities (CWE-253)

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 envoy

All envoy vulnerabilities

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