CVE-2021-27292
Regular Expression Denial of Service (ReDoS) in ua-parser-js
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- None
- User interaction
- None
What an attacker can affect
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Exploit likelihood
What each source reports
NVD Score used
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
CVE-2021-27292- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Updated
- 2026-11-02
CVE List No score
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
CVE-2021-27292- Updated
- 2026-11-02
EUVDEUVD-2021-0991 No score
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
EUVD-2021-0991- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-78cj-fxph-m83p
Regular Expression Denial of Service (ReDoS) in ua-parser-js
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
GHSA-78cj-fxph-m83p- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
OSV
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
CVE-2021-27292- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVDEBIAN-CVE-2021-27292
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
DEBIAN-CVE-2021-27292- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
Show 4 moreShow less
OSVGHSA-78cj-fxph-m83p
Regular Expression Denial of Service (ReDoS) in ua-parser-js
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
GHSA-78cj-fxph-m83p- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Weakness
- CWE-400
- Updated
- 2026-11-02
OSVUBUNTU-CVE-2021-27292
ua-parser-js >= 0.7.14, fixed in 0.7.24, uses a regular expression which is vulnerable to denial of service. If an attacker sends a malicious User-Agent header, ua-parser-js will get stuck processing it for an extended period of time.
- Record
UBUNTU-CVE-2021-27292- CVSS 3.1
- 7.5 High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - Updated
- 2026-11-02
OSVCLSA-2026-1774311649 No score
TuxCare security update for ua-parser-js (3 CVEs)
TuxCare rebuilt ua-parser-js to address 3 CVEs. Fixed in 0.7.21-tuxcare.1.
- Record
CLSA-2026-1774311649- Updated
- 2026-11-02
OSVCLSA-2026-1784596325 No score
TuxCare security update for ua-parser-js (2 CVEs)
TuxCare rebuilt ua-parser-js to address 2 CVEs. Fixed in 0.7.22-tuxcare.1.
- Record
CLSA-2026-1784596325- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
ua-parser-jsnpm |
0.7.14 up to 0.7.24 | 0.7.24 |
ua-parser-jsTuxCare:npm From an advisory covering 3 CVEs |
0.7.21-tuxcare.0 up to 0.7.21-tuxcare.1, plus listed versions 0.7.21 |
0.7.21-tuxcare.1 |
ua-parser-jsTuxCare:npm From an advisory covering 2 CVEs |
0.7.22-tuxcare.0 up to 0.7.22-tuxcare.1, plus listed versions 0.7.22 |
0.7.22-tuxcare.1 |
node-ua-parser-jsDebian:12 |
before 0.7.24+ds-1 | 0.7.24+ds-1 |
node-ua-parser-jsDebian:13 |
before 0.7.24+ds-1 | 0.7.24+ds-1 |
node-ua-parser-jsDebian:14 |
before 0.7.24+ds-1 | 0.7.24+ds-1 |
node-ua-parser-jsUbuntu:18.04:LTS |
All versions, plus listed versions 0.7.14-1 |
None known |
node-ua-parser-jsUbuntu:20.04:LTS |
All versions, plus listed versions 0.7.14-1 |
None known |
node-ua-parser-jsUbuntu:22.04:LTS |
All versions, plus listed versions 0.7.24+ds-10.7.24+ds-20.7.31+ds+~0.7.36-1 |
None known |
History
| Recorded | Changed | Sources |
|---|---|---|
| affected, facts | ||
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2021-27292 is a high vulnerability (CVSS 7.5) in Ua-parser-js Project Ua-parser-js, published March 17, 2021. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 3.37%, the 88th percentile. Fixed in ua-parser-js 0.7.24.
References
github.com/pygments/pygments/commit/2e7e8c4a7b318f4032493773732754e418279a14
gist.github.com/b-c-ds/6941d80d6b4e694df4bc269493b7be76
nvd.nist.gov/vuln/detail/CVE-2021-27292
security-tracker.debian.org/tracker/CVE-2021-27292
ubuntu.com/security/CVE-2021-27292
cve.org/CVERecord?id=CVE-2021-27292