CVE-2021-3749 | Inefficient Regular Expression Complexity in axios/axios

Exp

axios is vulnerable to Inefficient Regular Expression Complexity

Published: 2021-08-31 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2021-3749 is rated High Exploit Risk (78.6/100): CVSS High severity, with high exploitation likelihood (EPSS 8.52%, 94th percentile). Core evidence: 1 public exploit reference(s) are indexed (Exploit-DB). Mandatory action: Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-3749

EDB-ID Source Kind Published Link
nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-3749

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-24 7.93% 8.52% +0.58%
2 2026-06-15 8.89% 7.93% -0.96%
3 2026-05-05 8.89%

Full EPSS history (68 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-3749

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
7.5 3.0 HIGH
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.9 3.6 [email protected]
7.8 2.0 HIGH
AV:N/AC:L/Au:N/C:N/I:N/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:N)
No confidentiality impact.
Integrity impact (I:N)
No integrity impact.
Availability impact (A:C)
Complete availability impact.
10.0 6.9 [email protected]

Weakness enumeration for CVE-2021-3749

GitHub Security Advisory for CVE-2021-3749

GHSA-cph5-m8f7-6c5x · Severity: high · Ecosystem: npm — axios Inefficient Regular Expression Complexity vulnerability

OS Trackers for CVE-2021-3749

vendor priority summary link
debian not yet assigned CVE-2021-3749 not yet assigned priority: Debian including 1 source packages (node-axios), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2021-3749
redhat medium https://access.redhat.com/security/cve/CVE-2021-3749
ubuntu medium CVE-2021-3749 medium priority: Ubuntu including 1 source packages (node-axios), 15 status rows across 15 suites (bionic, focal, hirsute, impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, trusty, upstream, xenial): ignored 8, needs-triage 4, DNE 2, needed 1. https://ubuntu.com/security/CVE-2021-3749

Affected software / configurations for CVE-2021-3749

Vendor Product Version Raw CPE
axios axios <= 0.21.1 cpe:2.3:a:axios:axios:*:*:*:*:*:node.js:*:*
siemens sinec_ins < 1.0 cpe:2.3:a:siemens:sinec_ins:*:*:*:*:*:*:*:*
siemens sinec_ins 1.0 cpe:2.3:a:siemens:sinec_ins:1.0:-:*:*:*:*:*:*
siemens sinec_ins 1.0 cpe:2.3:a:siemens:sinec_ins:1.0:sp1:*:*:*:*:*:*
oracle goldengate >= 21.1, < 21.7.0.0.0 cpe:2.3:a:oracle:goldengate:*:*:*:*:*:*:*:*

References for CVE-2021-3749

URL Tags
https://cert-portal.siemens.com/productcert/pdf/ssa-637483.pdf Third Party Advisory
https://github.com/axios/axios/commit/5b457116e31db0e88fede6c428e969e87f290929 Patch Third Party Advisory
https://huntr.dev/bounties/1e8f07fc-c384-4ff9-8498-0690de2e8c31 Exploit Patch Third Party Advisory
https://lists.apache.org/thread.html/r075d464dce95cd13c03ff9384658edcccd5ab2983b82bfc72b62bb10%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/r216f0fd0a3833856d6a6a1fada488cadba45f447d87010024328ccf2%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/r3ae6d2654f92c5851bdb73b35e96b0e4e3da39f28ac7a1b15ae3aab8%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/r4bf1b32983f50be00f9752214c1b53738b621be1c2b0dbd68c7f2391%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/r7324ecc35b8027a51cb6ed629490fcd3b2d7cf01c424746ed5744bf1%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/r74d0b359408fff31f87445261f0ee13bdfcac7d66f6b8e846face321%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/ra15d63c54dc6474b29f72ae4324bcb03038758545b3ab800845de7a1%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/rc263bfc5b53afcb7e849605478d73f5556eb0c00d1f912084e407289%40%3Ccommits.druid.apache.org%3E
https://lists.apache.org/thread.html/rfa094029c959da0f7c8cd7dc9c4e59d21b03457bf0cedf6c93e1bb0a%40%3Cdev.druid.apache.org%3E
https://lists.apache.org/thread.html/rfc5c478053ff808671aef170f3d9fc9d05cc1fab8fb64431edc66103%40%3Ccommits.druid.apache.org%3E
https://www.oracle.com/security-alerts/cpujul2022.html Third Party Advisory
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