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Fencer Vulns
high 7.5

CVE-2023-37475 json

Attacker-controlled parameter can cause denial of service in hamba avro

published 2023-07-17 3 y ago modified 2026-09-10 1 mo ago also GHSA-9x44-9pgq-cf45 , GO-2023-1930 , EUVD-2023-2020

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

Hamba avro is a go lang encoder/decoder implementation of the avro codec specification. In affected versions a well-crafted string passed to avro's `github.com/hamba/avro/v2.Unmarshal()` can throw a `fatal error: runtime: out of memory` which is unrecoverable and can cause denial of service of the consumer of avro. The root cause of the issue is that avro uses part of the input to `Unmarshal()` to determine the size when creating a new slice and hence an attacker may consume arbitrary amounts of memory which in turn may cause the application to crash. This issue has been addressed in commit `b4a402f4` which has been included in release version `2.13.0`. Users are advised to upgrade. There are no known workarounds for this vulnerability.

Patch / fix

  • go github.com/hamba/avro 2.13.0
  • go github.com/hamba/avro/v2 2.13.0
  • avro_project avro 2.13.0

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
2 y ago

Exploit prediction

0.95% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/hamba/avro/security/advisories/GHSA-9x44-9pgq-cf45 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
go github.com/hamba/avro
<2.13.0
all versions
2.13.0
go github.com/hamba/avro/v2
<2.13.0
2.13.0

Affected products

  • hamba avro
  • avro_project avro

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.