CyberSecBulletin
CVE-2023-25933NVD status: Modified

Hermes: Access of Resource Using Incompatible Type

CVE-2023-25933 is a critical-severity access of resource using incompatible type vulnerability in Hermes from Facebook, with a CVSS 3.1 base score of 9.8 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 e6ed9c1a4b02dc219de1648f44cd808a56171b81 as the first without the flaw, so updating Hermes to that release or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.89% chance of exploitation within 30 days, higher than 60% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Hermes to e6ed9c1a4b02dc219de1648f44cd808a56171b81 or a later version.
  2. Read the advisory on facebook.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
FacebookHermesbefore e6ed9c1a4b02dc219de1648f44cd808a56171b81e6ed9c1a4b02dc219de1648f44cd808a56171b81

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
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:N/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.19.8CriticalNVD
CVSS 3.19.8CriticalCISA (ADP)

Official description

A type confusion bug in TypedArray prior to commit e6ed9c1a4b02dc219de1648f44cd808a56171b81 could have been used by a malicious attacker to execute arbitrary code via untrusted JavaScript. Note that this is only exploitable in cases where Hermes is used to execute untrusted JavaScript. Hence, most React Native applications are not affected.

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

The underlying weakness: Access of Resource Using Incompatible Type

The product allocates or initializes a resource such as a pointer, object, or variable using one type, but it later accesses that resource using a type that is incompatible with the original type.

More Access of Resource Using Incompatible Type vulnerabilities (CWE-843)

Timeline

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

References

Other vulnerabilities in Hermes

All Hermes vulnerabilities

Recent Access of Resource Using Incompatible Type vulnerabilities

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