CVE-2024-7531

Calling `PK11_Encrypt()` in NSS using CKM_CHACHA20 and the same buffer for input and output can result in plaintext on an Intel Sandy Bridge processor. In Firefox this only affects the QUIC header protection feature when the connection is using the ChaCha20-Poly1305 cipher suite. The most likely outcome is connection failure, but if the connection persists despite the high packet loss it could be possible for a network observer to identify packets as coming from the same source despite a network path change. This vulnerability affects Firefox < 129, Firefox ESR < 115.14, and Firefox ESR < 128.1.

Published: 2024-08-06 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2024-7531 is rated Low Risk (37.7/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.41%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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

Exploit prediction scoring system (EPSS) score for CVE-2024-7531

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 2026-06-15 0.05% 0.41% +0.36%
2 2025-11-21 0.24% 0.05% -0.19%
3 2025-11-18 — 0.24% —

Full EPSS history (8 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2024-7531

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
6.5 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N 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:R)
A real person has to do something—click, install, enable—otherwise it doesn’t land.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 3.6 [email protected]
6.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L 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:L)
A normal user session is enough; they don’t have to be admin.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
 2.8 3.4 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2024-7531

OS Trackers for CVE-2024-7531

vendor priority summary link
alpine — CVE-2024-7531: 2 source package rows (firefox, firefox-esr); 261 state rows across 3 repos (3.20-community, 3.22-community, edge-community); fixed 0, open 261. https://security.alpinelinux.org/vuln/CVE-2024-7531
debian unimportant CVE-2024-7531 unimportant priority: Debian including 3 source packages (firefox, firefox-esr, nss), 11 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 10, open 1. https://security-tracker.debian.org/tracker/CVE-2024-7531
gentoo high CVE-2024-7531: 3 GLSA(s) (202412-04, 202412-06, 202412-13), 5 atom(s) (dev-lang/spidermonkey, mail-client/thunderbird, mail-client/thunderbird-bin, www-client/firefox, www-client/firefox-bin); latest impact high. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2024-7531
redhat low — https://access.redhat.com/security/cve/CVE-2024-7531
suse high CVE-2024-7531 severity important: SUSE including 25 source package names (MozillaFirefox-128.1.0-112.221.1, MozillaFirefox-128.1.0-150200.152.146.1, …), 155 product×package rows across 44 product lines (Container suse/kiosk/firefox-esr, Image SLES12-SP5-SAP-Azure-LI-BYOS-Production, … (44 product lines)): Fixed 155. https://www.suse.com/security/cve/CVE-2024-7531/
ubuntu medium CVE-2024-7531 medium priority: Ubuntu including 9 source packages (firefox, mozjs102, …), 65 status rows across 8 suites (bionic, focal, jammy, noble, oracular, plucky, questing, upstream): DNE 34, needs-triage 11, not-affected 10, ignored 9, released 1. https://ubuntu.com/security/CVE-2024-7531

Affected software / configurations for CVE-2024-7531

Vendor Product Version Raw CPE
mozilla firefox < 129.0 cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*
mozilla firefox_esr < 115.14.0 cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*
mozilla firefox_esr 128.0 cpe:2.3:a:mozilla:firefox_esr:128.0:*:*:*:*:*:*:*

References for CVE-2024-7531

cvelogic Threat Intelligence