CVE-2021-28040: ossec Uncontrolled Recursion
CVSS: 7.5v3.1HighModified
Published 05-03-2021Last modified 03-08-2024
Vulnerability summary
CVE-2021-28040 is a high (CVSS 7.5) Uncontrolled Recursion vulnerability in ossec. EPSS estimates a 1.19% chance of exploitation in the next 30 days, higher than 67.5% of scored vulnerabilities. 1 public exploit is recorded.
CVSS score
7.5/10
010
High · v3.1 (NVD)EPSS score
1.19%
0%100%
Low · 0.00 pp in 30 daysKEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits1github
Timeline
- 05-03-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
An issue was discovered in OSSEC 3.6.0. An uncontrolled recursion vulnerability in os_xml.c occurs when a large number of opening and closing XML tags is used. Because recursion is used in _ReadElem without restriction, an attacker can trigger a segmentation fault once unmapped memory is reached.
CVSS metrics
2 scores · 1 source · 2 versionsHigh 7.5Preferred score · NVD (NIST)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HSourcesSingle source
Medium 5.0Preferred score · NVD (NIST)
AV:N/AC:L/Au:N/C:N/I:N/A:PSourcesSingle source
EPSS trend
Probability
1.19%
Chance of exploitation in the next 30 days
Percentile
68%
Versus all other CVEs
30-day change
0.00 pp
From 1.19% on 19-09-2026
19-09-202619-10-2026
EPSS score1.19%
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundOssec Hids
Maturity: poc
Weaknesses
CWE · root causeAffected systems
Ossec1 product
- ossec3.6.0
1 vendor · 1 product