7.5

CVE-2021-28903: cesnet libyang Uncontrolled Recursion

CVSS: 7.5v3.1HighModified
AliasesUBUNTU-CVE-2021-28903DEBIAN-CVE-2021-28903
Published 20-05-2021Last modified 03-08-2024
Open JSON

Vulnerability summary

CVE-2021-28903 is a high (CVSS 7.5) Uncontrolled Recursion vulnerability in cesnet libyang. EPSS estimates a 2.43% chance of exploitation in the next 30 days, higher than 83.9% of scored vulnerabilities. 1 public exploit is recorded.

Overall risk
40/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.5/10
010
High · v3.1 (NVD)
EPSS score
2.43%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github

Advisory lineage

Upstream 0 · Downstream 1 · Related 1
SUSE-SU-2022:3245-1

Timeline

  1. 20-05-2021
    PublishedVulnerability first disclosed.
  2. 03-08-2024
    Last modifiedVulnerability information updated.

Description

A stack overflow in libyang <= v1.0.225 can cause a denial of service through function lyxml_parse_mem(). lyxml_parse_elem() function will be called recursively, which will consume stack space and lead to crash.

CVSS metrics

4 scores · 3 sources · 2 versions

EPSS trend

Probability

2.43%

Chance of exploitation in the next 30 days

Percentile

84%

Versus all other CVEs

30-day change

0.00 pp

From 2.43% on 20-09-2026

20-09-202620-10-2026
EPSS score
2.43%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

1 found
  • githubUnverified

    Libyang

    Maturity: poc

Weaknesses

CWE · root cause

Affected systems

Cesnet1 product
Debian1 product
  • libyang< 3.4.2+dfsg-2
Ubuntu1 product
  • libyangAll versions (No fix recorded)

3 vendors · 3 products

References

5 links